Method and device for receiving ppdu having been subjected to ldpc tone mapping in broadband tone plan in wireless lan system

ABSTRACT

Proposed are a method and a device for receiving a PPDU having been subjected to LDPC tone mapping in a broadband tone plan in a wireless LAN system. Specifically, a reception STA receives a PPDU from a transmission STA through broadband and decodes the PPDU. A data tone included in a data field is subjected to LDPC tone mapping on the basis of a first parameter. A tone plan for the 240 MHz band is 3×996 tone RUs, and a tone plan for the 320 MHz band is 4×996 tone RUs. The first parameter is 20.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/597,390, filed on Jan. 4, 2022, which is the National Stage filingunder 35 U.S.C. 371 of International Application No. PCT/KR2020/007784,filed on Jun. 16, 2020, which claims the benefit of earlier filing dateand right of priority to Korean Patent Application No. 10-2019-0081615,filed on Jul. 5, 2019, the contents of which are all incorporated byreference herein in their entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to a method for receiving a physicallayer protocol data unit (PPDU) in a wideband in a wireless local areanetwork (WLAN) system and, most particularly, to a method and device forreceiving a PPDU having LDPC tone mapping performed in a tone plan of awideband.

Related Art

A wireless local area network (WLAN) has been improved in various ways.For example, the IEEE 802.11ax standard proposed an improvedcommunication environment using orthogonal frequency division multipleaccess (OFDMA) and downlink multi-user multiple input multiple output(DL MU MIMO) techniques.

The present specification proposes a technical feature that can beutilized in a new communication standard. For example, the newcommunication standard may be an extreme high throughput (EHT) standardwhich is currently being discussed. The EHT standard may use anincreased bandwidth, an enhanced PHY layer protocol data unit (PPDU)structure, an enhanced sequence, a hybrid automatic repeat request(HARQ) scheme, or the like, which is newly proposed. The EHT standardmay be called the IEEE 802.11be standard.

In a new WLAN standard, an increased number of spatial streams may beused. In this case, in order to properly use the increased number ofspatial streams, a signaling technique in the WLAN system may need to beimproved.

SUMMARY OF THE DISCLOSURE Technical Objects

The present specification proposes a method and device for receiving aPPDU having LDPC tone mapping performed in a tone plan of a wideband ina WLAN system.

Technical Solutions

An example of the present specification proposes a method for receivinga PPDU in a wideband.

The present embodiment proposes a method for performing LDPC tonemapping for a data bit sequence that is included in a data field of aPPDU, when the PPDU is transmitted at a wideband (240 MHz, 320 MHz band)that is supported by an EHT WLAN system. At this point, a tone plan ofthe wideband may be designed by repeating (or iterating) an 80 MHz toneplan of 802.11ax.

An example of the present embodiment may be performed by a receivingstation (STA), and the receiving STA may correspond to an STA thatsupports an Extremely High Throughput (EHT) WLAN system. A transmittingSTA of the present embodiment may correspond to an access point (AP).

A receiving STA receives a Physical Protocol Data Unit (PPDU) from atransmitting STA through a wideband.

The receiving STA decodes the PPDU.

The wideband may be a 240 MHz band or a 320 MHz band.

The PPDU may include a control field and a data field. The control fieldmay include a Universal-Signal (U-SIG) field and an EHT-SIG field.

Low Density Parity Check (LDPC) tone mapping is performed on data tonesincluded in the data field based on a first parameter. Morespecifically, the data field may be generated based on a bit stream. Thebit stream may be mapped to the data tones based on a constellationmapping. The data tones may be configured to have a tone spacing that isequivalent to the first parameter based on the LDPC tone mapping. TheLDPC tone mapping is similar to an interleaving operation, and the bitstream may be spread at a tone spacing of the first parameter based onthe LDPC tone mapping and may then be mapped to a data tone.Additionally, the bit stream may be modulated based on the constellationmapping before being processed with the LDPC tone mapping.

Furthermore, the bit stream may be divided per frequency segment by asegment parser before the constellation mapping is performed. Theconstellation mapping and the LDPC tone mapping may be performed perfrequency segment. A size of one frequency segment may be equal to a996-tone RU.

Effects of the Disclosure

According to the embodiment proposed in the present specification, byproposing an LDPC tone mapping parameter the present disclosure in awideband, a data tone that is optimized in light of frequency diversitymay be obtained through LDPC tone mapping. And, thus, a new effect ofincreasing overall throughput may be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a transmitting apparatus and/or receivingapparatus of the present specification.

FIG. 2 is a conceptual view illustrating the structure of a wirelesslocal area network (WLAN).

FIG. 3 illustrates a general link setup process.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20MHz.

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

FIG. 8 illustrates a structure of an HE-SIG-B field.

FIG. 9 illustrates an example in which a plurality of user STAs areallocated to the same RU through a MU-MIMO scheme.

FIG. 10 illustrates an operation based on UL-MU.

FIG. 11 illustrates an example of a trigger frame.

FIG. 12 illustrates an example of a common information field of atrigger frame.

FIG. 13 illustrates an example of a subfield included in a per userinformation field.

FIG. 14 describes a technical feature of the UORA scheme.

FIG. 15 illustrates an example of a channel used/supported/definedwithin a 2.4 GHz band.

FIG. 16 illustrates an example of a channel used/supported/definedwithin a 5 GHz band.

FIG. 17 illustrates an example of a channel used/supported/definedwithin a 6 GHz band.

FIG. 18 illustrates an example of a PPDU used in the presentspecification.

FIG. 19 shows an example of a PHY transmission procedure for HE SU PPDU.

FIG. 20 shows an example of a block diagram of a transmitting device forgenerating each field of an HE PPDU.

FIG. 21 shows an example of an LDPC tone mapping operation.

FIG. 22 shows an example of a DCM method being applied to data.

FIG. 23 shows an example of LDPC tone mapping having tone spacing set to3 in a 52-tone RU in a situation where DCM is not applied.

FIG. 24 shows an example of LDPC tone mapping having tone spacing set to3 in a 106-tone RU in a situation where DCM is applied.

FIG. 25 is a procedure flowchart showing operations of a transmittingdevice according to the present embodiment.

FIG. 26 is a procedure flowchart showing operations of a receivingdevice according to the present embodiment.

FIG. 27 shows a flowchart showing a procedure of transmitting, by atransmitting STA, a PPDU in a wideband according to the presentembodiment.

FIG. 28 shows a flowchart showing a procedure of receiving, by areceiving STA, a PPDU in a wideband according to the present embodiment.

FIG. 29 illustrates an example of a modified transmitting device and/orreceiving device of the present specification.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the present specification, “A or B” may mean “only A”, “only B” or“both A and B”. In other words, in the present specification, “A or B”may be interpreted as “A and/or B”. For example, in the presentspecification, “A, B, or C” may mean “only A”, “only B”, “only C”, or“any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean“and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B”may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C”may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “onlyA”, “only B”, or “both A and B”. In addition, in the presentspecification, the expression “at least one of A or B” or “at least oneof A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C”may mean “only A”, “only B”, “only C”, or “any combination of A, B, andC”. In addition, “at least one of A, B, or C” or “at least one of A, B,and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean“for example”. Specifically, when indicated as “control information(EHT-signal)”, it may mean that “EHT-signal”is proposed as an example ofthe “control information”. In other words, the “control information” ofthe present specification is not limited to “EHT-signal”, and“EHT-signal” may be proposed as an example of the “control information”.In addition, when indicated as “control information (i.e., EHT-signal)”,it may also mean that “EHT-signal” is proposed as an example of the“control information”.

Technical features described individually in one figure in the presentspecification may be individually implemented, or may be simultaneouslyimplemented.

The following example of the present specification may be applied tovarious wireless communication systems. For example, the followingexample of the present specification may be applied to a wireless localarea network (WLAN) system. For example, the present specification maybe applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11axstandard. In addition, the present specification may also be applied tothe newly proposed EHT standard or IEEE 802.11be standard. In addition,the example of the present specification may also be applied to a newWLAN standard enhanced from the EHT standard or the IEEE 802.11bestandard. In addition, the example of the present specification may beapplied to a mobile communication system. For example, it may be appliedto a mobile communication system based on long term evolution (LTE)depending on a 3rd generation partnership project (3GPP) standard andbased on evolution of the LTE. In addition, the example of the presentspecification may be applied to a communication system of a 5G NRstandard based on the 3GPP standard.

Hereinafter, in order to describe a technical feature of the presentspecification, a technical feature applicable to the presentspecification will be described.

FIG. 1 shows an example of a transmitting apparatus and/or receivingapparatus of the present specification.

In the example of FIG. 1 , various technical features described belowmay be performed. FIG. 1 relates to at least one station (STA). Forexample, STAs 110 and 120 of the present specification may also becalled in various terms such as a mobile terminal, a wireless device, awireless transmit/receive unit (WTRU), a user equipment (UE), a mobilestation (MS), a mobile subscriber unit, or simply a user. The STAs 110and 120 of the present specification may also be called in various termssuch as a network, a base station, a node-B, an access point (AP), arepeater, a router, a relay, or the like. The STAs 110 and 120 of thepresent specification may also be referred to as various names such as areceiving apparatus, a transmitting apparatus, a receiving STA, atransmitting STA, a receiving device, a transmitting device, or thelike.

For example, the STAs 110 and 120 may serve as an AP or a non-AP. Thatis, the STAs 110 and 120 of the present specification may serve as theAP and/or the non-AP.

STAs 110 and 120 of the present specification may support variouscommunication standards together in addition to the IEEE 802.11standard. For example, a communication standard (e.g., LTE, LTE-A, 5G NRstandard) or the like based on the 3GPP standard may be supported. Inaddition, the STA of the present specification may be implemented asvarious devices such as a mobile phone, a vehicle, a personal computer,or the like. In addition, the STA of the present specification maysupport communication for various communication services such as voicecalls, video calls, data communication, and self-driving(autonomous-driving), or the like.

The STAs 110 and 120 of the present specification may include a mediumaccess control (MAC) conforming to the IEEE 802.11 standard and aphysical layer interface for a radio medium.

The STAs 110 and 120 will be described below with reference to asub-figure (a) of FIG. 1 .

The first STA 110 may include a processor 111, a memory 112, and atransceiver 113. The illustrated process, memory, and transceiver may beimplemented individually as separate chips, or at least twoblocks/functions may be implemented through a single chip.

The transceiver 113 of the first STA performs a signaltransmission/reception operation. Specifically, an IEEE 802.11 packet(e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the first STA 110 may perform an operation intended by anAP. For example, the processor 111 of the AP may receive a signalthrough the transceiver 113, process a reception (RX) signal, generate atransmission (TX) signal, and provide control for signal transmission.The memory 112 of the AP may store a signal (e.g., RX signal) receivedthrough the transceiver 113, and may store a signal (e.g., TX signal) tobe transmitted through the transceiver.

For example, the second STA 120 may perform an operation intended by anon-AP STA. For example, a transceiver 123 of a non-AP performs a signaltransmission/reception operation. Specifically, an IEEE 802.11 packet(e.g., IEEE 802.11a/b/g/n/ac/ax/be packet, etc.) may betransmitted/received.

For example, a processor 121 of the non-AP STA may receive a signalthrough the transceiver 123, process an RX signal, generate a TX signal,and provide control for signal transmission. A memory 122 of the non-APSTA may store a signal (e.g., RX signal) received through thetransceiver 123, and may store a signal (e.g., TX signal) to betransmitted through the transceiver.

For example, an operation of a device indicated as an AP in thespecification described below may be performed in the first STA 110 orthe second STA 120. For example, if the first STA 110 is the AP, theoperation of the device indicated as the AP may be controlled by theprocessor 111 of the first STA 110, and a related signal may betransmitted or received through the transceiver 113 controlled by theprocessor 111 of the first STA 110. In addition, control informationrelated to the operation of the AP or a TX/RX signal of the AP may bestored in the memory 112 of the first STA 110. In addition, if thesecond STA 120 is the AP, the operation of the device indicated as theAP may be controlled by the processor 121 of the second STA 120, and arelated signal may be transmitted or received through the transceiver123 controlled by the processor 121 of the second STA 120. In addition,control information related to the operation of the AP or a TX/RX signalof the AP may be stored in the memory 122 of the second STA 120.

For example, in the specification described below, an operation of adevice indicated as a non-AP (or user-STA) may be performed in the firstSTA 110 or the second STA 120. For example, if the second STA 120 is thenon-AP, the operation of the device indicated as the non-AP may becontrolled by the processor 121 of the second STA 120, and a relatedsignal may be transmitted or received through the transceiver 123controlled by the processor 121 of the second STA 120. In addition,control information related to the operation of the non-AP or a TX/RXsignal of the non-AP may be stored in the memory 122 of the second STA120. For example, if the first STA 110 is the non-AP, the operation ofthe device indicated as the non-AP may be controlled by the processor111 of the first STA 110, and a related signal may be transmitted orreceived through the transceiver 113 controlled by the processor 111 ofthe first STA 110. In addition, control information related to theoperation of the non-AP or a TX/RX signal of the non-AP may be stored inthe memory 112 of the first STA 110.

In the specification described below, a device called a(transmitting/receiving) STA, a first STA, a second STA, a STA1, a STA2,an AP, a first AP, a second AP, an AP1, an AP2, a(transmitting/receiving) terminal, a (transmitting/receiving) device, a(transmitting/receiving) apparatus, a network, or the like may imply theSTAs 110 and 120 of FIG. 1 . For example, a device indicated as, withouta specific reference numeral, the (transmitting/receiving) STA, thefirst STA, the second STA, the STA1, the STA2, the AP, the first AP, thesecond AP, the AP1, the AP2, the (transmitting/receiving) terminal, the(transmitting/receiving) device, the (transmitting/receiving) apparatus,the network, or the like may imply the STAs 110 and 120 of FIG. 1 . Forexample, in the following example, an operation in which various STAstransmit/receive a signal (e.g., a PPDU) may be performed in thetransceivers 113 and 123 of FIG. 1 . In addition, in the followingexample, an operation in which various STAs generate a TX/RX signal orperform data processing and computation in advance for the TX/RX signalmay be performed in the processors 111 and 121 of FIG. 1 . For example,an example of an operation for generating the TX/RX signal or performingthe data processing and computation in advance may include: 1) anoperation ofdetermining/obtaining/configuring/computing/decoding/encoding bitinformation of a sub-field (SIG, STF, LTF, Data) included in a PPDU; 2)an operation of determining/configuring/obtaining a time resource orfrequency resource (e.g., a subcarrier resource) or the like used forthe sub-field (SIG, STF, LTF, Data) included the PPDU; 3) an operationof determining/configuring/obtaining a specific sequence (e.g., a pilotsequence, an STF/LTF sequence, an extra sequence applied to SIG) or thelike used for the sub-field (SIG, STF, LTF, Data) field included in thePPDU; 4) a power control operation and/or power saving operation appliedfor the STA; and 5) an operation related todetermining/obtaining/configuring/decoding/encoding or the like of anACK signal. In addition, in the following example, a variety ofinformation used by various STAs fordetermining/obtaining/configuring/computing/decoding/decoding a TX/RXsignal (e.g., information related to a field/subfield/controlfield/parameter/power or the like) may be stored in the memories 112 and122 of FIG. 1 .

The aforementioned device/STA of the sub-figure (a) of FIG. 1 may bemodified as shown in the sub-figure (b) of FIG. 1 . Hereinafter, theSTAs 110 and 120 of the present specification will be described based onthe sub-figure (b) of FIG. 1 .

For example, the transceivers 113 and 123 illustrated in the sub-figure(b) of FIG. 1 may perform the same function as the aforementionedtransceiver illustrated in the sub-figure (a) of FIG. 1 . For example,processing chips 114 and 124 illustrated in the sub-figure (b) of FIG. 1may include the processors 111 and 121 and the memories 112 and 122. Theprocessors 111 and 121 and memories 112 and 122 illustrated in thesub-figure (b) of FIG. 1 may perform the same function as theaforementioned processors 111 and 121 and memories 112 and 122illustrated in the sub-figure (a) of FIG. 1 .

A mobile terminal, a wireless device, a wireless transmit/receive unit(WTRU), a user equipment (UE), a mobile station (MS), a mobilesubscriber unit, a user, a user STA, a network, a base station, aNode-B, an access point (AP), a repeater, a router, a relay, a receivingunit, a transmitting unit, a receiving STA, a transmitting STA, areceiving device, a transmitting device, a receiving apparatus, and/or atransmitting apparatus, which are described below, may imply the STAs110 and 120 illustrated in the sub-figure (a)/(b) of FIG. 1 , or mayimply the processing chips 114 and 124 illustrated in the sub-figure (b)of FIG. 1 . That is, a technical feature of the present specificationmay be performed in the STAs 110 and 120 illustrated in the sub-figure(a)/(b) of FIG. 1 , or may be performed only in the processing chips 114and 124 illustrated in the sub-figure (b) of FIG. 1 . For example, atechnical feature in which the transmitting STA transmits a controlsignal may be understood as a technical feature in which a controlsignal generated in the processors 111 and 121 illustrated in thesub-figure (a)/(b) of FIG. 1 is transmitted through the transceivers 113and 123 illustrated in the sub-figure (a)/(b) of FIG. 1 . Alternatively,the technical feature in which the transmitting STA transmits thecontrol signal may be understood as a technical feature in which thecontrol signal to be transferred to the transceivers 113 and 123 isgenerated in the processing chips 114 and 124 illustrated in thesub-figure (b) of FIG. 1 .

For example, a technical feature in which the receiving STA receives thecontrol signal may be understood as a technical feature in which thecontrol signal is received by means of the transceivers 113 and 123illustrated in the sub-figure (a) of FIG. 1 . Alternatively, thetechnical feature in which the receiving STA receives the control signalmay be understood as the technical feature in which the control signalreceived in the transceivers 113 and 123 illustrated in the sub-figure(a) of FIG. 1 is obtained by the processors 111 and 121 illustrated inthe sub-figure (a) of FIG. 1 . Alternatively, the technical feature inwhich the receiving STA receives the control signal may be understood asthe technical feature in which the control signal received in thetransceivers 113 and 123 illustrated in the sub-figure (b) of FIG. 1 isobtained by the processing chips 114 and 124 illustrated in thesub-figure (b) of FIG. 1 .

Referring to the sub-figure (b) of FIG. 1 , software codes 115 and 125may be included in the memories 112 and 122. The software codes 115 and126 may include instructions for controlling an operation of theprocessors 111 and 121. The software codes 115 and 125 may be includedas various programming languages.

The processors 111 and 121 or processing chips 114 and 124 of FIG. 1 mayinclude an application-specific integrated circuit (ASIC), otherchipsets, a logic circuit and/or a data processing device. The processormay be an application processor (AP). For example, the processors 111and 121 or processing chips 114 and 124 of FIG. 1 may include at leastone of a digital signal processor (DSP), a central processing unit(CPU), a graphics processing unit (GPU), and a modulator and demodulator(modem). For example, the processors 111 and 121 or processing chips 114and 124 of FIG. 1 may be SNAPDRAGON™ series of processors made byQualcomm®, EXYNOS™ series of processors made by Samsung®, A series ofprocessors made by Apple®, HELIO™ series of processors made byMediaTek®, ATOM™ series of processors made by Intel® or processorsenhanced from these processors.

In the present specification, an uplink may imply a link forcommunication from a non-AP STA to an SP STA, and an uplinkPPDU/packet/signal or the like may be transmitted through the uplink. Inaddition, in the present specification, a downlink may imply a link forcommunication from the AP STA to the non-AP STA, and a downlinkPPDU/packet/signal or the like may be transmitted through the downlink.

FIG. 2 is a conceptual view illustrating the structure of a wirelesslocal area network (WLAN).

An upper part of FIG. 2 illustrates the structure of an infrastructurebasic service set (BSS) of institute of electrical and electronicengineers (i.e. EE) 802.11.

Referring the upper part of FIG. 2 , the wireless LAN system may includeone or more infrastructure BSSs 200 and 205 (hereinafter, referred to asBSS). The BSSs 200 and 205 as a set of an AP and a STA such as an accesspoint (AP) 225 and a station (STA1) 200-1 which are successfullysynchronized to communicate with each other are not concepts indicatinga specific region. The BSS 205 may include one or more STAs 205-1 and205-2 which may be joined to one AP 230.

The BSS may include at least one STA, APs providing a distributionservice, and a distribution system (DS) 210 connecting multiple APs.

The distribution system 210 may implement an extended service set (ESS)240 extended by connecting the multiple BSSs 200 and 205. The ESS 240may be used as a term indicating one network configured by connectingone or more APs 225 or 230 through the distribution system 210. The APincluded in one ESS 240 may have the same service set identification(SSID).

A portal 220 may serve as a bridge which connects the wireless LANnetwork (i.e. EE 802.11) and another network (e.g., 802.X).

In the BSS illustrated in the upper part of FIG. 2 , a network betweenthe APs 225 and 230 and a network between the APs 225 and 230 and theSTAs 200-1, 205-1, and 205-2 may be implemented. However, the network isconfigured even between the STAs without the APs 225 and 230 to performcommunication. A network in which the communication is performed byconfiguring the network even between the STAs without the APs 225 and230 is defined as an Ad-Hoc network or an independent basic service set(IBS S).

A lower part of FIG. 2 illustrates a conceptual view illustrating theIBSS.

Referring to the lower part of FIG. 2 , the IBSS is a BSS that operatesin an Ad-Hoc mode. Since the IBSS does not include the access point(AP), a centralized management entity that performs a managementfunction at the center does not exist. That is, in the IBSS, STAs 250-1,250-2, 250-3, 255-4, and 255-5 are managed by a distributed manner. Inthe IBSS, all STAs 250-1, 250-2, 250-3, 255-4, and 255-5 may beconstituted by movable STAs and are not permitted to access the DS toconstitute a self-contained network.

FIG. 3 illustrates a general link setup process.

In S310, a STA may perform a network discovery operation. The networkdiscovery operation may include a scanning operation of the STA. Thatis, to access a network, the STA needs to discover a participatingnetwork. The STA needs to identify a compatible network beforeparticipating in a wireless network, and a process of identifying anetwork present in a particular area is referred to as scanning.Scanning methods include active scanning and passive scanning.

FIG. 3 illustrates a network discovery operation including an activescanning process. In active scanning, a STA performing scanningtransmits a probe request frame and waits for a response to the proberequest frame in order to identify which AP is present around whilemoving to channels. A responder transmits a probe response frame as aresponse to the probe request frame to the STA having transmitted theprobe request frame. Here, the responder may be a STA that transmits thelast beacon frame in a BSS of a channel being scanned. In the BSS, sincean AP transmits a beacon frame, the AP is the responder. In an IBSS,since STAs in the IBSS transmit a beacon frame in turns, the responderis not fixed. For example, when the STA transmits a probe request framevia channel 1 and receives a probe response frame via channel 1, the STAmay store BS S-related information included in the received proberesponse frame, may move to the next channel (e.g., channel 2), and mayperform scanning (e.g., transmits a probe request and receives a proberesponse via channel 2) by the same method.

Although not shown in FIG. 3 , scanning may be performed by a passivescanning method. In passive scanning, a STA performing scanning may waitfor a beacon frame while moving to channels. A beacon frame is one ofmanagement frames in IEEE 802.11 and is periodically transmitted toindicate the presence of a wireless network and to enable the STAperforming scanning to find the wireless network and to participate inthe wireless network. In a BSS, an AP serves to periodically transmit abeacon frame. In an IBSS, STAs in the IBSS transmit a beacon frame inturns. Upon receiving the beacon frame, the STA performing scanningstores information about a BSS included in the beacon frame and recordsbeacon frame information in each channel while moving to anotherchannel. The STA having received the beacon frame may store BSS-relatedinformation included in the received beacon frame, may move to the nextchannel, and may perform scanning in the next channel by the samemethod.

After discovering the network, the STA may perform an authenticationprocess in S320. The authentication process may be referred to as afirst authentication process to be clearly distinguished from thefollowing security setup operation in S340. The authentication processin S320 may include a process in which the STA transmits anauthentication request frame to the AP and the AP transmits anauthentication response frame to the STA in response. The authenticationframes used for an authentication request/response are managementframes.

The authentication frames may include information about anauthentication algorithm number, an authentication transaction sequencenumber, a status code, a challenge text, a robust security network(RSN), and a finite cyclic group.

The STA may transmit the authentication request frame to the AP. The APmay determine whether to allow the authentication of the STA based onthe information included in the received authentication request frame.The AP may provide the authentication processing result to the STA viathe authentication response frame.

When the STA is successfully authenticated, the STA may perform anassociation process in S330. The association process includes a processin which the STA transmits an association request frame to the AP andthe AP transmits an association response frame to the STA in response.The association request frame may include, for example, informationabout various capabilities, a beacon listen interval, a service setidentifier (SSID), a supported rate, a supported channel, RSN, amobility domain, a supported operating class, a traffic indication map(TIM) broadcast request, and an interworking service capability. Theassociation response frame may include, for example, information aboutvarious capabilities, a status code, an association ID (AID), asupported rate, an enhanced distributed channel access (EDCA) parameterset, a received channel power indicator (RCPI), a receivedsignal-to-noise indicator (RSNI), a mobility domain, a timeout interval(association comeback time), an overlapping BSS scanning parameter, aTIM broadcast response, and a QoS map.

In S340, the STA may perform a security setup process. The securitysetup process in S340 may include a process of setting up a private keythrough four-way handshaking, for example, through an extensibleauthentication protocol over LAN (EAPOL) frame.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard.

As illustrated, various types of PHY protocol data units (PPDUs) areused in IEEE a/g/n/ac standards. Specifically, an LTF and a STF includea training signal, a SIG-A and a SIG-B include control information for areceiving STA, and a data field includes user data corresponding to aPSDU (MAC PDU/aggregated MAC PDU).

FIG. 4 also includes an example of an HE PPDU according to IEEE802.11ax. The HE PPDU according to FIG. 4 is an illustrative PPDU formultiple users. An HE-SIG-B may be included only in a PPDU for multipleusers, and an HE-SIG-B may be omitted in a PPDU for a single user.

As illustrated in FIG. 4 , the HE-PPDU for multiple users (MUs) mayinclude a legacy-short training field (L-STF), a legacy-long trainingfield (L-LTF), a legacy-signal (L-SIG), a high efficiency-signal A(HE-SIG A), a high efficiency-signal-B (HE-SIG B), a highefficiency-short training field (HE-STF), a high efficiency-longtraining field (HE-LTF), a data field (alternatively, an MAC payload),and a packet extension (PE) field. The respective fields may betransmitted for illustrated time periods (i.e., 4 or 8 μs).

Hereinafter, a resource unit (RU) used for a PPDU is described. An RUmay include a plurality of subcarriers (or tones). An RU may be used totransmit a signal to a plurality of STAs according to OFDMA. Further, anRU may also be defined to transmit a signal to one STA. An RU may beused for an STF, an LTF, a data field, or the like.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20MHz.

As illustrated in FIG. 5 , resource units (RUs) corresponding todifferent numbers of tones (i.e., subcarriers) may be used to form somefields of an HE-PPDU. For example, resources may be allocated inillustrated RUs for an HE-STF, an HE-LTF, and a data field.

As illustrated in the uppermost part of FIG. 5 , a 26-unit (i.e., a unitcorresponding to 26 tones) may be disposed. Six tones may be used for aguard band in the leftmost band of the 20 MHz band, and five tones maybe used for a guard band in the rightmost band of the 20 MHz band.Further, seven DC tones may be inserted in a center band, that is, a DCband, and a 26-unit corresponding to 13 tones on each of the left andright sides of the DC band may be disposed. A 26-unit, a 52-unit, and a106-unit may be allocated to other bands. Each unit may be allocated fora receiving STA, that is, a user.

The layout of the RUs in FIG. 5 may be used not only for multiple users(MUs) but also for a single user (SU), in which case one 242-unit may beused and three DC tones may be inserted as illustrated in the lowermostpart of FIG. 5 .

Although FIG. 5 proposes RUs having various sizes, that is, a 26-RU, a52-RU, a 106-RU, and a 242-RU, specific sizes of RUs may be extended orincreased. Therefore, the present embodiment is not limited to thespecific size of each RU (i.e., the number of corresponding tones).

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

Similarly to FIG. 5 in which RUs having various sizes are used, a 26-RU,a 52-RU, a 106-RU, a 242-RU, a 484-RU, and the like may be used in anexample of FIG. 6 . Further, five DC tones may be inserted in a centerfrequency, 12 tones may be used for a guard band in the leftmost band ofthe 40 MHz band, and 11 tones may be used for a guard band in therightmost band of the 40 MHz band.

As illustrated in FIG. 6 , when the layout of the RUs is used for asingle user, a 484-RU may be used. The specific number of RUs may bechanged similarly to FIG. 5 .

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

Similarly to FIG. 5 and FIG. 6 in which RUs having various sizes areused, a 26-RU, a 52-RU, a 106-RU, a 242-RU, a 484-RU, a 996-RU, and thelike may be used in an example of FIG. 7 . Further, seven DC tones maybe inserted in the center frequency, 12 tones may be used for a guardband in the leftmost band of the 80 MHz band, and 11 tones may be usedfor a guard band in the rightmost band of the 80 MHz band. In addition,a 26-RU corresponding to 13 tones on each of the left and right sides ofthe DC band may be used.

As illustrated in FIG. 7 , when the layout of the RUs is used for asingle user, a 996-RU may be used, in which case five DC tones may beinserted.

The RU described in the present specification may be used in uplink (UL)communication and downlink (DL) communication. For example, when UL-MUcommunication which is solicited by a trigger frame is performed, atransmitting STA (e.g., an AP) may allocate a first RU (e.g.,26/52/106/242-RU, etc.) to a first STA through the trigger frame, andmay allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA.Thereafter, the first STA may transmit a first trigger-based PPDU basedon the first RU, and the second STA may transmit a second trigger-basedPPDU based on the second RU. The first/second trigger-based PPDU istransmitted to the AP at the same (or overlapped) time period.

For example, when a DL MU PPDU is configured, the transmitting STA(e.g., AP) may allocate the first RU (e.g., 26/52/106/242-RU. etc.) tothe first STA, and may allocate the second RU (e.g., 26/52/106/242-RU,etc.) to the second STA. That is, the transmitting STA (e.g., AP) maytransmit HE-STF, HE-LTF, and Data fields for the first STA through thefirst RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Datafields for the second STA through the second RU.

Information related to a layout of the RU may be signaled throughHE-SIG-B.

FIG. 8 illustrates a structure of an HE-SIG-B field.

As illustrated, an HE-SIG-B field 810 includes a common field 820 and auser-specific field 830. The common field 820 may include informationcommonly applied to all users (i.e., user STAs) which receive SIG-B. Theuser-specific field 830 may be called a user-specific control field.When the SIG-B is transferred to a plurality of users, the user-specificfield 830 may be applied only any one of the plurality of users.

As illustrated in FIG. 8 , the common field 820 and the user-specificfield 830 may be separately encoded.

The common field 820 may include RU allocation information of N*8 bits.For example, the RU allocation information may include informationrelated to a location of an RU. For example, when a 20 MHz channel isused as shown in FIG. 5 , the RU allocation information may includeinformation related to a specific frequency band to which a specific RU(26-RU/52-RU/106-RU) is arranged.

An example of a case in which the RU allocation information consists of8 bits is as follows.

TABLE 1 RU Allocation subfield (B7 B6 B5 B4 Number B3 B2 B1 B0) #1 #2 #3#4 #5 #6 #7 #8 #9 of entries 00000000 26 26 26 26 26 26 26 26 26 100000001 26 26 26 26 26 26 26 52 1 00000010 26 26 26 26 26 52 26 26 100000011 26 26 26 26 26 52 52 1 00000100 26 26 52 26 26 26 26 26 100000101 26 26 52 26 26 26 52 1 00000110 26 26 52 26 52 26 26 1 0000011126 26 52 26 52 52 1 00001000 52 26 26 26 26 26 26 26 1 00001001 52 26 2626 26 26 52 1 00001010 52 26 26 26 52 26 26 1

As shown the example of FIG. 5 , up to nine 26-RUs may be allocated tothe 20 MHz channel. When the RU allocation information of the commonfield 820 is set to “00000000” as shown in Table 1, the nine 26-RUs maybe allocated to a corresponding channel (i.e., 20 MHz). In addition,when the RU allocation information of the common field 820 is set to“00000001” as shown in Table 1, seven 26-RUs and one 52-RU are arrangedin a corresponding channel. That is, in the example of FIG. 5 , the52-RU may be allocated to the rightmost side, and the seven 26-RUs maybe allocated to the left thereof.

The example of Table 1 shows only some of RU locations capable ofdisplaying the RU allocation information.

For example, the RU allocation information may include an example ofTable 2 below.

TABLE 2 8 bits indices B7 B6 B5 B4 Number B3 B2 B1 B0) #1 #2 #3 #4 #5 #6#7 #8 #9 of entries z z z z z z z z z z z 01000y₂y₁y₀ 106 26 26 26 26 268 01001y₂y₁y₀ 106 26 26 26 52 8

“01000y2y1y0” relates to an example in which a 106-RU is allocated tothe leftmost side of the 20 MHz channel, and five 26-RUs are allocatedto the right side thereof. In this case, a plurality of STAs (e.g.,user-STAs) may be allocated to the 106-RU, based on a MU-MIMO scheme.Specifically, up to 8 STAs (e.g., user-STAs) may be allocated to the106-RU, and the number of STAs (e.g., user-STAs) allocated to the 106-RUis determined based on 3-bit information (y2y1y0). For example, when the3-bit information (y2y1y0) is set to N, the number of STAs (e.g.,user-STAs) allocated to the 106-RU based on the MU-MIMO scheme may beN+1.

In general, a plurality of STAs (e.g., user STAs) different from eachother may be allocated to a plurality of RUs. However, the plurality ofSTAs (e.g., user STAs) may be allocated to one or more RUs having atleast a specific size (e.g., 106 subcarriers), based on the MU-MIMOscheme.

As shown in FIG. 8 , the user-specific field 830 may include a pluralityof user fields. As described above, the number of STAs (e.g., user STAs)allocated to a specific channel may be determined based on the RUallocation information of the common field 820. For example, when the RUallocation information of the common field 820 is “00000000”, one userSTA may be allocated to each of nine 26-RUs (e.g., nine user STAs may beallocated). That is, up to 9 user STAs may be allocated to a specificchannel through an OFDMA scheme. In other words, up to 9 user STAs maybe allocated to a specific channel through a non-MU-MIMO scheme.

For example, when RU allocation is set to “01000y2y1y0”, a plurality ofSTAs may be allocated to the 106-RU arranged at the leftmost sidethrough the MU-MIMO scheme, and five user STAs may be allocated to five26-RUs arranged to the right side thereof through the non-MU MIMOscheme. This case is specified through an example of FIG. 9 .

FIG. 9 illustrates an example in which a plurality of user STAs areallocated to the same RU through a MU-MIMO scheme.

For example, when RU allocation is set to “01000010” as shown in FIG. 9, a 106-RU may be allocated to the leftmost side of a specific channel,and five 26-RUs may be allocated to the right side thereof. In addition,three user STAs may be allocated to the 106-RU through the MU-MIMOscheme. As a result, since eight user STAs are allocated, theuser-specific field 830 of HE-SIG-B may include eight user fields.

The eight user fields may be expressed in the order shown in FIG. 9 . Inaddition, as shown in FIG. 8 , two user fields may be implemented withone user block field.

The user fields shown in FIG. 8 and FIG. 9 may be configured based ontwo formats. That is, a user field related to a MU-MIMO scheme may beconfigured in a first format, and a user field related to a non-MIMOscheme may be configured in a second format. Referring to the example ofFIG. 9 , a user field 1 to a user field 3 may be based on the firstformat, and a user field 4 to a user field 8 may be based on the secondformat. The first format or the second format may include bitinformation of the same length (e.g., 21 bits).

Each user field may have the same size (e.g., 21 bits). For example, theuser field of the first format (the first of the MU-MIMO scheme) may beconfigured as follows.

For example, a first bit (i.e., B0-B10) in the user field (i.e., 21bits) may include identification information (e.g., STA-ID, partial AID,etc.) of a user STA to which a corresponding user field is allocated. Inaddition, a second bit (i.e., B11-B14) in the user field (i.e., 21 bits)may include information related to a spatial configuration.Specifically, an example of the second bit (i.e., B11-B14) may be asshown in Table 3 and Table 4 below.

TABLE 3 N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS)Total Number N_(user) B3 . . . B0 [1] [2] [3] [4] [5] [6] [7] [8]N_(STS) of entries 2 0000-0011 1-4 1 z z z z 2-5 10 0100-0110 2-4 2 4-60111-1000 3-4 3 6-7 1001 4 4 8 3 0000-0011 1-4 1 1 3-6 13 0100-0110 2-42 1 5-7 0111-1000 3-4 3 1 7-8 1001-1011 2-4 2 2 6-8 1100 3 3 2 8 40000-0011 1-4 1 1 1 4-7 11 0100-0110 2-4 2 1 1 6-8 0111 3 3 1 1 81000-1001 2-3 2 2 1 7-8 1010 2 2 2 2 8

TABLE 4 N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS) N_(STS)Total Number N_(user) B3 . . . B0 [1] [2] [3] [4] [5] [6] [7] [8]N_(STS) of entries 5 0000-0011 1-4 1 1 1 1 5-8 7 0100-0101 2-3 2 1 1 17-8 0110 2 2 2 1 1 8 6 0000-0010 1-3 1 1 1 1 1 6-8 4 0011 2 2 1 1 1 1 87 0000-0001 1-2 1 1 1 1 1 1 7-8 2 8 0000 1 1 1 1 1 1 1 1 8 1

As shown in Table 3 and/or Table 4, the second bit (e.g., B11-B14) mayinclude information related to the number of spatial streams allocatedto the plurality of user STAs which are allocated based on the MU-MIMOscheme. For example, when three user STAs are allocated to the 106-RUbased on the MU-MIMO scheme as shown in FIG. 9 , N user is set to “3”.Therefore, values of N_STS[1], N_STS[2], and N_STS[3] may be determinedas shown in Table 3. For example, when a value of the second bit(B11-B14) is “0011”, it may be set to N_STS[1]=4, N_STS[2]=1,N_STS[3]=1. That is, in the example of FIG. 9 , four spatial streams maybe allocated to the user field 1, one spatial stream may be allocated tothe user field 1, and one spatial stream may be allocated to the userfield 3.

As shown in the example of Table 3 and/or Table 4, information (i.e.,the second bit, B11-B14) related to the number of spatial streams forthe user STA may consist of 4 bits. In addition, the information (i.e.,the second bit, B11-B14) on the number of spatial streams for the userSTA may support up to eight spatial streams. In addition, theinformation (i.e., the second bit, B11-B14) on the number of spatialstreams for the user STA may support up to four spatial streams for oneuser STA.

In addition, a third bit (i.e., B15-18) in the user field (i.e., 21bits) may include modulation and coding scheme (MCS) information. TheMCS information may be applied to a data field in a PPDU includingcorresponding SIG-B.

An MCS, MCS information, an MCS index, an MCS field, or the like used inthe present specification may be indicated by an index value. Forexample, the MCS information may be indicated by an index 0 to an index11. The MCS information may include information related to aconstellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM,256-QAM, 1024-QAM, etc.) and information related to a coding rate (e.g.,½, ⅔, ¾, ⅚e, etc.). Information related to a channel coding type (e.g.,LCC or LDPC) may be excluded in the MCS information.

In addition, a fourth bit (i.e., B19) in the user field (i.e., 21 bits)may be a reserved field.

In addition, a fifth bit (i.e., B20) in the user field (i.e., 21 bits)may include information related to a coding type (e.g., BCC or LDPC).That is, the fifth bit (i.e., B20) may include information related to atype (e.g., BCC or LDPC) of channel coding applied to the data field inthe PPDU including the corresponding SIG-B.

The aforementioned example relates to the user field of the first format(the format of the MU-MIMO scheme). An example of the user field of thesecond format (the format of the non-MU-MIMO scheme) is as follows.

A first bit (e.g., B0-B10) in the user field of the second format mayinclude identification information of a user STA. In addition, a secondbit (e.g., B11-B13) in the user field of the second format may includeinformation related to the number of spatial streams applied to acorresponding RU. In addition, a third bit (e.g., B14) in the user fieldof the second format may include information related to whether abeamforming steering matrix is applied. A fourth bit (e.g., B15-B18) inthe user field of the second format may include modulation and codingscheme (MCS) information. In addition, a fifth bit (e.g., B19) in theuser field of the second format may include information related towhether dual carrier modulation (DCM) is applied. In addition, a sixthbit (i.e., B20) in the user field of the second format may includeinformation related to a coding type (e.g., BCC or LDPC).

FIG. 10 illustrates an operation based on UL-MU. As illustrated, atransmitting STA (e.g., an AP) may perform channel access throughcontending (e.g., a backoff operation), and may transmit a trigger frame1030. That is, the transmitting STA may transmit a PPDU including thetrigger frame 1030. Upon receiving the PPDU including the trigger frame,a trigger-based (TB) PPDU is transmitted after a delay corresponding toSIFS.

TB PPDUs 1041 and 1042 may be transmitted at the same time period, andmay be transmitted from a plurality of STAs (e.g., user STAs) havingAIDs indicated in the trigger frame 1030. An ACK frame 1050 for the TBPPDU may be implemented in various forms.

A specific feature of the trigger frame is described with reference toFIG. 11 to FIG. 13 . Even if UL-MU communication is used, an orthogonalfrequency division multiple access (OFDMA) scheme or a MU MIMO schememay be used, and the OFDMA and MU-MIMO schemes may be simultaneouslyused.

FIG. 11 illustrates an example of a trigger frame. The trigger frame ofFIG. 11 allocates a resource for uplink multiple-user (MU) transmission,and may be transmitted, for example, from an AP. The trigger frame maybe configured of a MAC frame, and may be included in a PPDU.

Each field shown in FIG. 11 may be partially omitted, and another fieldmay be added. In addition, a length of each field may be changed to bedifferent from that shown in the figure.

A frame control field 1110 of FIG. 11 may include information related toa MAC protocol version and extra additional control information. Aduration field 1120 may include time information for NAV configurationor information related to an identifier (e.g., AID) of a STA.

In addition, an RA field 1130 may include address information of areceiving STA of a corresponding trigger frame, and may be optionallyomitted. A TA field 1140 may include address information of a STA (e.g.,an AP) which transmits the corresponding trigger frame. A commoninformation field 1150 includes common control information applied tothe receiving STA which receives the corresponding trigger frame. Forexample, a field indicating a length of an L-SIG field of an uplink PPDUtransmitted in response to the corresponding trigger frame orinformation for controlling content of a SIG-A field (i.e., HE-SIG-Afield) of the uplink PPDU transmitted in response to the correspondingtrigger frame may be included. In addition, as common controlinformation, information related to a length of a CP of the uplink PPDUtransmitted in response to the corresponding trigger frame orinformation related to a length of an LTF field may be included.

In addition, per user information fields 1160 #1 to 1160 #Ncorresponding to the number of receiving STAs which receive the triggerframe of FIG. 11 are preferably included. The per user information fieldmay also be called an “allocation field”.

In addition, the trigger frame of FIG. 11 may include a padding field1170 and a frame check sequence field 1180.

Each of the per user information fields 1160 #1 to 1160 #N shown in FIG.11 may include a plurality of subfields.

FIG. 12 illustrates an example of a common information field of atrigger frame. A subfield of FIG. 12 may be partially omitted, and anextra subfield may be added. In addition, a length of each subfieldillustrated may be changed.

A length field 1210 illustrated has the same value as a length field ofan L-SIG field of an uplink PPDU transmitted in response to acorresponding trigger frame, and a length field of the L-SIG field ofthe uplink PPDU indicates a length of the uplink PPDU. As a result, thelength field 1210 of the trigger frame may be used to indicate thelength of the corresponding uplink PPDU.

In addition, a cascade identifier field 1220 indicates whether a cascadeoperation is performed. The cascade operation implies that downlink MUtransmission and uplink MU transmission are performed together in thesame TXOP. That is, it implies that downlink MU transmission isperformed and thereafter uplink MU transmission is performed after apre-set time (e.g., SIFS). During the cascade operation, only onetransmitting device (e.g., AP) may perform downlink communication, and aplurality of transmitting devices (e.g., non-APs) may perform uplinkcommunication.

A CS request field 1230 indicates whether a wireless medium state or aNAV or the like is necessarily considered in a situation where areceiving device which has received a corresponding trigger frametransmits a corresponding uplink PPDU.

An HE-SIG-A information field 1240 may include information forcontrolling content of a SIG-A field (i.e., HE-SIG-A field) of theuplink PPDU in response to the corresponding trigger frame.

A CP and LTF type field 1250 may include information related to a CPlength and LTF length of the uplink PPDU transmitted in response to thecorresponding trigger frame. A trigger type field 1260 may indicate apurpose of using the corresponding trigger frame, for example, typicaltriggering, triggering for beamforming, a request for block ACK/NACK, orthe like.

It may be assumed that the trigger type field 1260 of the trigger framein the present specification indicates a trigger frame of a basic typefor typical triggering. For example, the trigger frame of the basic typemay be referred to as a basic trigger frame.

FIG. 13 illustrates an example of a subfield included in a per userinformation field. A user information field 1300 of FIG. 13 may beunderstood as any one of the per user information fields 1160 #1 to 1160#N mentioned above with reference to FIG. 11 . A subfield included inthe user information field 1300 of FIG. 13 may be partially omitted, andan extra subfield may be added. In addition, a length of each subfieldillustrated may be changed.

A user identifier field 1310 of FIG. 13 indicates an identifier of a STA(i.e., receiving STA) corresponding to per user information. An exampleof the identifier may be the entirety or part of an associationidentifier (AID) value of the receiving STA.

In addition, an RU allocation field 1320 may be included. That is, whenthe receiving STA identified through the user identifier field 1310transmits a TB PPDU in response to the trigger frame, the TB PPDU istransmitted through an RU indicated by the RU allocation field 1320. Inthis case, the RU indicated by the RU allocation field 1320 may be an RUshown in FIG. 5 , FIG. 6 , and FIG. 7 .

The subfield of FIG. 13 may include a coding type field 1330. The codingtype field 1330 may indicate a coding type of the TB PPDU. For example,when BCC coding is applied to the TB PPDU, the coding type field 1330may be set to ‘1’, and when LDPC coding is applied, the coding typefield 1330 may be set to ‘0’.

In addition, the subfield of FIG. 13 may include an MCS field 1340. TheMCS field 1340 may indicate an MCS scheme applied to the TB PPDU. Forexample, when BCC coding is applied to the TB PPDU, the coding typefield 1330 may be set to ‘1’, and when LDPC coding is applied, thecoding type field 1330 may be set to ‘0’.

Hereinafter, a UL OFDMA-based random access (UORA) scheme will bedescribed.

FIG. 14 describes a technical feature of the UORA scheme.

A transmitting STA (e.g., an AP) may allocate six RU resources through atrigger frame as shown in FIG. 14 . Specifically, the AP may allocate a1st RU resource (AID 0, RU 1), a 2nd RU resource (AID 0, RU 2), a 3rd RUresource (AID 0, RU 3), a 4th RU resource (AID 2045, RU 4), a 5th RUresource (AID 2045, RU 5), and a 6th RU resource (AID 3, RU 6).Information related to the AID 0, AID 3, or AID 2045 may be included,for example, in the user identifier field 1310 of FIG. 13 . Informationrelated to the RU 1 to RU 6 may be included, for example, in the RUallocation field 1320 of FIG. 13 . AID=0 may imply a UORA resource foran associated STA, and AID=2045 may imply a UORA resource for anun-associated STA. Accordingly, the 1st to 3rd RU resources of FIG. 14may be used as a UORA resource for the associated STA, the 4th and 5thRU resources of FIG. 14 may be used as a UORA resource for theun-associated STA, and the 6th RU resource of FIG. 14 may be used as atypical resource for UL MU.

In the example of FIG. 14 , an OFDMA random access backoff (OBO) of aSTA1 is decreased to 0, and the STA1 randomly selects the 2nd RUresource (AID 0, RU 2). In addition, since an OBO counter of a STA2/3 isgreater than 0, an uplink resource is not allocated to the STA2/3. Inaddition, regarding a STA4 in FIG. 14 , since an AID (e.g., AID=3) ofthe STA4 is included in a trigger frame, a resource of the RU 6 isallocated without backoff.

Specifically, since the STA1 of FIG. 14 is an associated STA, the totalnumber of eligible RA RUs for the STA1 is 3 (RU 1, RU 2, and RU 3), andthus the STA1 decreases an OBO counter by 3 so that the OBO counterbecomes 0. In addition, since the STA2 of FIG. 14 is an associated STA,the total number of eligible RA RUs for the STA2 is 3 (RU 1, RU 2, andRU 3), and thus the STA2 decreases the OBO counter by 3 but the OBOcounter is greater than 0. In addition, since the STA3 of FIG. 14 is anun-associated STA, the total number of eligible RA RUs for the STA3 is 2(RU 4, RU 5), and thus the STA3 decreases the OBO counter by 2 but theOBO counter is greater than 0.

FIG. 15 illustrates an example of a channel used/supported/definedwithin a 2.4 GHz band.

The 2.4 GHz band may be called in other terms such as a first band. Inaddition, the 2.4 GHz band may imply a frequency domain in whichchannels of which a center frequency is close to 2.4 GHz (e.g., channelsof which a center frequency is located within 2.4 to 2.5 GHz) areused/supported/defined.

A plurality of 20 MHz channels may be included in the 2.4 GHz band. 20MHz within the 2.4 GHz may have a plurality of channel indices (e.g., anindex 1 to an index 14). For example, a center frequency of a 20 MHzchannel to which a channel index 1 is allocated may be 2.412 GHz, acenter frequency of a 20 MHz channel to which a channel index 2 isallocated may be 2.417 GHz, and a center frequency of a 20 MHz channelto which a channel index N is allocated may be (2.407+0.005*N) GHz. Thechannel index may be called in various terms such as a channel number orthe like. Specific numerical values of the channel index and centerfrequency may be changed.

FIG. 15 exemplifies 4 channels within a 2.4 GHz band. Each of 1st to 4thfrequency domains 1510 to 1540 shown herein may include one channel. Forexample, the 1st frequency domain 1510 may include a channel 1 (a 20 MHzchannel having an index 1). In this case, a center frequency of thechannel 1 may be set to 2412 MHz. The 2nd frequency domain 1520 mayinclude a channel 6. In this case, a center frequency of the channel 6may be set to 2437 MHz. The 3rd frequency domain 1530 may include achannel 11. In this case, a center frequency of the channel 11 may beset to 2462 MHz. The 4th frequency domain 1540 may include a channel 14.In this case, a center frequency of the channel 14 may be set to 2484MHz.

FIG. 16 illustrates an example of a channel used/supported/definedwithin a 5 GHz band.

The 5 GHz band may be called in other terms such as a second band or thelike. The 5 GHz band may imply a frequency domain in which channels ofwhich a center frequency is greater than or equal to 5 GHz and less than6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively,the 5 GHz band may include a plurality of channels between 4.5 GHz and5.5 GHz. A specific numerical value shown in FIG. 16 may be changed.

A plurality of channels within the 5 GHz band include an unlicensednational information infrastructure (UNII)-1, a UNII-2, a UNII-3, and anISM. The INII-1 may be called UNII Low. The UNII-2 may include afrequency domain called UNII Mid and UNII-2 Extended. The UNII-3 may becalled UNII-Upper.

A plurality of channels may be configured within the 5 GHz band, and abandwidth of each channel may be variously set to, for example, 20 MHz,40 MHz, 80 MHz, 160 MHz, or the like. For example, 5170 MHz to 5330 MHzfrequency domains/ranges within the UNII-1 and UNII-2 may be dividedinto eight 20 MHz channels. The 5170 MHz to 5330 MHz frequencydomains/ranges may be divided into four channels through a 40 MHzfrequency domain. The 5170 MHz to 5330 MHz frequency domains/ranges maybe divided into two channels through an 80 MHz frequency domain.Alternatively, the 5170 MHz to 5330 MHz frequency domains/ranges may bedivided into one channel through a 160 MHz frequency domain.

FIG. 17 illustrates an example of a channel used/supported/definedwithin a 6 GHz band.

The 6 GHz band may be called in other terms such as a third band or thelike. The 6 GHz band may imply a frequency domain in which channels ofwhich a center frequency is greater than or equal to 5.9 GHz areused/supported/defined. A specific numerical value shown in FIG. 17 maybe changed.

For example, the 20 MHz channel of FIG. 17 may be defined starting from5.940 GHz. Specifically, among 20 MHz channels of FIG. 17 , the leftmostchannel may have an index 1 (or a channel index, a channel number,etc.), and 5.945 GHz may be assigned as a center frequency. That is, acenter frequency of a channel of an index N may be determined as(5.940+0.005*N) GHz.

Accordingly, an index (or channel number) of the 2 MHz channel of FIG.17 may be 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61,65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125,129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181,185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Inaddition, according to the aforementioned (5.940+0.005*N) GHz rule, anindex of the 40 MHz channel of FIG. 17 may be 3, 11, 19, 27, 35, 43, 51,59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171,179, 187, 195, 203, 211, 219, 227.

Although 20, 40, 80, and 160 MHz channels are illustrated in the exampleof FIG. 17 , a 240 MHz channel or a 320 MHz channel may be additionallyadded.

Hereinafter, a PPDU transmitted/received in a STA of the presentspecification will be described.

FIG. 18 illustrates an example of a PPDU used in the presentspecification.

The PPDU of FIG. 18 may be referred to as various terms, such as EHTPPDU, transmitting PPDU, receiving PPDU, first type or Nth type PPDU,and so on. For example, in the present specification, PPDU or EHT PPDUmay be referred to by using various terms, such as transmission PPDU,reception PPDU, first type or Nth type PPDU, and so on. Additionally,the EHT PPDU may be used in an EHT system and/or a new WLAN system,which is an enhanced version of the EHT system.

The PPDU of FIG. 18 may represent part or all of a PPDU type that isused in an EHT system. For example, the example of FIG. 18 may be usedfor both single-user (SU) mode and multi-user (MU) mode, or may be usedonly for the SU mode, or may be used only for the MU mode. For example,in the EHT system, a trigger-based (TB) PPDU may be separately definedor may be configured based on an example of FIG. 18 . A trigger frameand UL-MU operations that are started by the trigger frame (e.g.,transmitting operations of the TB PPDU), which are described by at leastone of FIG. 10 to FIG. 14 , may be directly applied to the EHT systemwithout modification.

In FIG. 18 , L-STF to EHT-LTF may be referred to as a preamble orphysical preamble, and the L-STF to EHT-LTF may begenerated/transmitted/received/obtained/decoded in a physical layer.

Subcarrier spacing of the L-LTF, L-STF, L-SIG, RL-SIG, U-SIG, andEHT-SIG fields of FIG. 18 may be determined as 312.5 kHz, and subcarrierspacing of the EHT-STF, EHT-LTF, Data fields may be determined as 78.125kHz. That is, tone indexes (or subcarrier indexes) of the L-STF, L-LTF,L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be indicated in 312.5 kHzunits, and tone indexes (or subcarrier indexes) of the EHT-STF, EHT-LTF,Data fields may be indicated in 78.125 kHz units.

In the PPDU of FIG. 18 , L-LTF and L-STF may be the same as the fieldsof the prior art (or related art).

The L-SIG field of FIG. 18 may, for example, include 24 bits of bitinformation. For example, the 24-bit information may include a 4-bitRate field, 1 Reserved bit, a 12-bit Length field, 1 Parity bit, and 6Tail bits. For example, the 12-bit Length field may include informationrelated to a PPDU length or time duration. For example, a value of the12-bit Length field may be determined based on a type of the PPDU. Forexample, in case the PPDU is a non-HT PPDU, an HT PPDU, a VHT PPDU, oran EHT PPDU, the value of the Length field may be determined as amultiple of 3. For example, in case the PPDU is an HE PPDU, the value ofthe Length field may be determined as “a multiple of 3+1” or “a multipleof 3+2”. In other words, a value of the Length field for a non-HT PPDU,an HT PPDU, a VHT PPDU, or an EHT PPDU may be determined as a multipleof 3, and a value of the Length field for an HE PPDU may be determinedas “a multiple of 3+1” or “a multiple of 3+2”.

For example, a transmitting STA may apply BCC encoding, which is basedon a ½-code rate for 24-bit information of the L-SIG field. Afterwards,the transmitting STA may obtain 48 bits of BCC encoding bits. Then, BPSKmodulation may be applied to the 48 encoding bits so as to generate 48BPSK symbols. The transmitting STA may map the 48 BPSK symbols topositions excluding a pilot subcarrier {Subcarrier indexes −21, −7, +7,+21} and a DC subcarrier {Subcarrier index 0}. As a result, the 48 BPSKsymbols may be mapped to subcarrier indexes −26 to −22, −20 to −8, −6 to−1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA mayadditionally map a signal of {−1, −1, −1, 1} to subcarrier indexes {−28,−27, +27, +28}. The aforementioned signal may be used for channelestimation for a frequency domain corresponding to {−28, −27, +27, +28}.

The transmitting STA may generate an RL-SIG, which is generatedidentically as the L-SIG. The receiving STA may know that the receptionPPDU is an HE PPDU or EHT PPDU based on the presence (or existence) ofan RL-SIG.

A Universal SIG (U-SIG) may be inserted after the RL-SIG of FIG. 18 .The U-SIG may also be referred to by using various terms, such as afirst SIG field, a first SIG, a first-type SIG, a control signal, acontrol signal field, a first (type) control signal, and so on.

The U-SIG may include N-bit information and may also include informationfor identifying the EHT PPDU type. For example, the U-SIG may beconfigured based on 2 symbols (e.g., two contiguous OFDM symbols). Eachsymbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 us.Each symbol of the U-SIG may be used for transmitting 26-bitinformation. For example, each symbol of the U-SIG may betransmitted/received based on 52 data tones and 4 pilot tones.

For example, A-bit information (e.g., 52 un-coded bits) may betransmitted through the U-SIG (or U-SIG field), and a first symbol ofthe U-SIG may transmit first X-bit information (e.g., 26 un-coded bits)among the total of A bits of the corresponding information, and a secondsymbol of the U-SIG may transmit remaining Y-bit information (e.g., 26un-coded bits) of the A-bit information. For example, the transmittingSTA may obtain 26 un-coded bits that are included in each U-SIG symbol.The transmitting STA may perform convolutional encoding (i.e., BCCencoding) based on a rate of R=½ so as to generate 52-coded bits, and,then, the transmitting STA may perform interleaving on the 52-codedbits. The transmitting STA may perform BPSK modulation on theinterleaved 52-coded bits, so as to generate 52 BPSK symbols that areallocated to each U-SIG symbol. One U-SIG symbol may be transmittedbased on 56 tones (subcarriers) starting from subcarrier index −28 tosubcarrier index +28, with the exception for DC index 0. The 52 BPSKsymbols that are generated by the transmitting STA may be transmittedbased on the remaining tones (subcarriers) excluding the pilot tones−21, −7, +7, +21 tones.

For example, the A-bit information (e.g., 52 un-coded bits) may includea CRC field (e.g., 4-bit length field) and a Tail field (e.g., 6-bitlength field). The CRC field and the Tail field may be transmittedthrough the second symbol of the U-SIG. The CRC field may be generatedbased on the 26 bits being allocated to the first symbol of the U-SIGand the remaining 16 bits excluding the CRC/Tail fields from the secondsymbol. And, the CRC field may be generated based on the related art CRCcalculation algorithm. Additionally, the Tail field may be used forterminating a trellis of a convolutional decoder and may, for example,be configured as “000000”.

The A-bit information (e.g., 52 un-coded bits) being transmitted by theU-SIG (or U-SIG field) may be divided into version-independent bits andversion-dependent bits. For example, a size of the version-independentbits may be fixed or variable. For example, the version-independent bitsmay be allocated only to the first symbol of the U-SIG or may beallocated to both the first and second symbols of the U-SIG. Forexample, the version-independent bits and the version-dependent bits maybe referred to by using various terms, such as a first control bit and asecond control bit.

For example, the version-independent bits of the U-SIG may include a3-bit PHY version identifier. For example, the 3-bit PHY versionidentifier may include information related to the PHY version of thetransmission/reception PPDU. For example, a first value of the 3-bit PHYversion identifier may indicate that the transmission/reception PPDU isan EHT PPDU. In other words, when the transmitting STA transmits the EHTPPDU, the transmitting STA may set the 3-bit PHY version identifier tothe first value. In other words, based on the PHY version identifierhaving the first value, the receiving STA may determine that thereception PPDU is an EHT PPDU.

For example, the version-independent bits of the U-SIG may include a1-bit UL/DL flag field. A first value of the 1-bit UL/DL flag field isrelated to UL communication, and a second value of the 1-bit UL/DL flagfield is related to DL communication.

For example, the version-independent bits of the U-SIG may includeinformation related to the length of a TXOP, and information related toBSS color ID.

For example, in case the EHT PPDU is divided into various types (e.g.,EHT PPDU related to SU mode, EHT PPDU related to MU mode, EHT PPDUrelated to a Trigger Frame, EHT PPDU related to Extended Rangetransmission, and so on), information related to the EHT PPDU type maybe included in the version-dependent bits of the U-SIG.

For example, the U-SIG may include information related to 1) a bandwidthfield including information related to a bandwidth, 2) a field includinginformation related to an MCS scheme being applied to the EHT-SIG, 3) anindication field including information related to whether or not a dualsubcarrier modulation (DCM) scheme is applied to the EHT-SIG, 4) a fieldincluding information related to a number of symbols being used for theEHT-SIG, 5) a field including information related to whether or not theEHT-SIG is generated throughout the whole band, 6) a field includinginformation related to an EHT-LTF/STF type, 7) a field indicating anEHT-LTF length and a CP length.

Preamble puncturing may be applied to the PPDU of FIG. 18 . Preamblepuncturing means applying puncturing to a partial band (e.g., aSecondary 20 MHz band) of the whole band of a PPDU. For example, when an80 MHz PPDU is transmitted, the STA may apply puncturing to a secondary20 MHz band of the 80 MHz band and may transmit the PPDU only through aprimary 20 MHz band and a secondary 40 MHz band.

For example, a pattern of preamble puncturing may be preset (orpredetermined). For example, when a first puncturing pattern is applied,the puncturing may be applied only for a secondary 20 MHz band withinthe 80 MHz band. For example, when a second puncturing pattern isapplied, the puncturing may be applied to only one of the two secondary20 MHz bands that are included in the secondary 40 MHz band within the80 MHz band. For example, when a third puncturing pattern is applied,the puncturing may be applied only to a secondary 20 MHz band that isincluded in a primary 80 MHz band within a 160 MHz band (or 80+80 MHzband). For example, when a fourth puncturing pattern is applied, andwhen a primary 40 MHz band that is included in a primary 80 MHz bandwithin a 160 MHz band (or 80+80 MHz band) is present, the puncturing maybe applied to at least one 20 MHz channel that does not belong to theprimary 40 MHz band.

Information related to the preamble puncturing that is applied to thePPDU may be included in the U-SIG and/or EHT-SIG. For example, a firstfield of the U-SIG may include information related to a contiguousbandwidth of the PPDU, and a second field of the U-SIG may includeinformation related to preamble puncturing that is applied to the PPDU.

For example, the U-SIG and EHT-SIG may include information related topreamble puncturing based on the following method. When the bandwidth ofa PPDU exceeds 80 MHz, the U-SIG may be separately configured in 80 MHzunits. For example, when the bandwidth of a PPDU is 160 MHz, a firstU-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHzband may be included in the corresponding PPDU. In this case, a firstfield of the first U-SIG may include information related to the 160 MHzbandwidth, and a second field of the first U-SIG may include informationrelated to preamble puncturing (i.e., information related to a preamblepuncturing pattern) that is applied to the first 80 MHz band.Additionally, a first field of the second U-SIG may include informationrelated to the 160 MHz bandwidth, and a second field of the second U-SIGmay include information related to preamble puncturing (i.e.,information related to a preamble puncturing pattern) that is applied tothe second 80 MHz band. Meanwhile, an EHT-SIG that is contiguous to thefirst U-SIG may include information related to preamble puncturing(i.e., information related to a preamble puncturing pattern) that isapplied to the second 80 MHz band, and an EHT-SIG that is contiguous tothe second U-SIG may include information related to preamble puncturing(i.e., information related to a preamble puncturing pattern) that isapplied to the first 80 MHz band.

Additionally or alternatively, the U-SIG and EHT-SIG may includeinformation related to preamble puncturing based on the followingmethod. The U-SIG may include information related to preamble puncturing(i.e., information related to a preamble puncturing pattern) for allbands. That is, the EHT-SIG may not include information related topreamble puncturing, and only the U-SIG may include information relatedto preamble puncturing (i.e., information related to a preamblepuncturing pattern).

The U-SIG may be configured of 20 MHz units. For example, when an 80 MHzPPDU is configured, the U-SIG may be duplicated. That is, 4 identicalU-SIGs may be included in the 80 MHz PPDU. A PPDU that exceeds the 80MHz bandwidth may include different U-SIGs.

The EHT-SIG of FIG. 18 may include the technical features of anHE-SIG-B, which is indicated in the examples of FIG. 8 to FIG. 9 , asthey are. The EHT-SIG may also be referred to by using various terms,such as a second SIG field, a second SIG, a second-type SIG, a controlsignal, a control signal field, a second (type) control signal, and soon.

The EHT-SIG may include N-bit information (e.g., 1-bit information)related to whether an EHT PPDU supports the SU mode or whether an EHTPPDU supports the MU mode.

The EHT-SIG may be configured based on various MCS schemes. As describedabove, the information related to the MCS scheme being applied to theEHT-SIG may be included in the U-SIG. The EHT-SIG may be configuredbased on a DCM scheme. For example, among N number of data tones (e.g.,52 data tones) that are allocated for the EHT-SIG, a first modulationscheme may be applied to one half of contiguous tones, and a secondmodulation scheme may be applied to the remaining half of contiguoustones. That is, the transmitting STA may modulate specific controlinformation to a first symbol based on the first modulation scheme andmay allocate the modulated first symbol to one half of contiguous tones.Thereafter, the transmitting STA may modulate the same controlinformation to a second symbol based on the second modulation scheme andmay allocated the modulated second symbol to the other half ofcontiguous tones. As described above, information related to whether ornot the DCM scheme is applied to the EHT-SIG (e.g., 1 bit field) may beincluded in the U-SIG. EHT-STF of FIG. 18 may be used for enhancingautomatic gain control estimation in a multiple input multiple output(MIMO) environment or OFDMA environment. And, EHT-LTF of FIG. 18 may beused for estimating a channel in a MIMO environment or OFDMAenvironment.

The EHT-STF may be set to various types. For example, among the STFs, afirst type (i.e., 1×STF) may be generated based on a first type STFsequence in which non-zero coefficients are positioned at 16 subcarrierspacings. An STF signal that is generated based on the first type STFsequence may have a periodicity (or cycle period) of 0.8 μs. And, thesignal having the periodicity of 0.8 μs may be repeated 5 times andbecome a first type STF having a length of 4 μs. For example, among theSTFs, a second type (i.e., 2×STF) may be generated based on a secondtype STF sequence in which non-zero coefficients are positioned at 8subcarrier spacings. An STF signal that is generated based on the secondtype STF sequence may have a periodicity (or cycle period) of 1.6 μs.And, the signal having the periodicity of 1.6 μs may be repeated 5 timesand become a second type STF having a length of 8 μs. Hereinafter, anexample of a sequence (i.e., EHT-STF sequence) for configuring anEHT-STF will be proposed. The following sequence may be modified tovarious types.

The EHT-STF may be configured based on the following M sequence.

M={−1,−1,−1,1,1,1,−1,1,1,1,−1,1,1,−1,1}  <Equation 1>

An EHT-STF for a 20 MHz PPDU may be configured based on the followingequation. The example shown below may be a first type (i.e., 1×STF)sequence. For example, the first type sequence may be included in anEHT-PPDU and not a trigger-based (TB) PPDU. In the following equation,(a:b:c) may denote durations being defined at b tone spacings (i.e.,subcarrier spacings) starting from an a tone index (i.e., subcarrierindex) to a c tone index. For example, Equation 2 shown below mayrepresent a sequence that is defined at 16 tone spacings starting fromtone index −112 to tone index 112. For an EHT-STF, since subcarrierspacing of 78.125 kHz is applied, the 16 tone spacings may mean thatEHT-STF coefficients (or elements) are positioned at 78.125*16=1250 kHzintervals (or spacings). Additionally,*means multiplication (i.e.,‘multiplied by’), and sqrt( ) means square root.

EHT-STF(−112: 16: 112)={M}*(1+j)/sqrt(2)

EHT-STF(0)=0  <Equation 2>

An EHT-STF for a 40 MHz PPDU may be configured based on the followingequation. The example shown below may be a first type (i.e., 1×STF)sequence.

EHT-STF(−240: 16: 240)={M,0,−M}*(1+j)/sqrt(2)  <Equation 3>

An EHT-STF for an 80 MHz PPDU may be configured based on the followingequation. The example shown below may be a first type (i.e., 1×STF)sequence.

EHT-STF(−496:16:496)={M,1,−M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation 4>

An EHT-STF for a 160 MHz PPDU may be configured based on the followingequation. The example shown below may be a first type (i.e., 1×STF)sequence.

EHT-STF(−1008:16:1008)={M,1,−M,0,−M,1,−M,0,−M,−1,M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation5>

In the EHT-STF for an 80+80 MHz PPDU, a sequence for a lower 80 MHz maybe the same as Equation 4. And, in the EHT-STF for the 80+80 MHz PPDU, asequence for a higher 80 MHz may be configured based on the followingequation.

EHT-STF(−496:16:496)={−M,−1,M,0,−M,1,−M}*(1+j)/sqrt(2)  <Equation 6>

Hereinafter, Equation 7 to Equation 11 relate to examples of a secondtype (i.e., 2×STF) sequence.

EHT-STF(−120: 8: 120)={M,0,−M}*(1+j)/sqrt(2)  <Equation 7>

An EHT-STF for a 40 MHz PPDU may be configured based on the followingequation.

EHT-STF(−248:8:248)={M,−1,−M,0,M,−1,M}*(1+j)/sqrt(2)

EHT-STF(−248)=0

EHT-STF(248)=0  <Equation 8>

An EHT-STF for an 80 MHz PPDU may be configured based on the followingequation.

EHT-STF(−504:8:504)={M,−1,M,−1,−M,−1,M,0,−M,1,M,1,−M,1,−M}*(1+j)/sqrt(2)  <Equation9>

An EHT-STF for a 160 MHz PPDU may be configured based on the followingequation.

EHT-STF(−1016:16:1016)={M,−1,M,−1,−M,−1,M,0,−M,1,M,1,−M,1,−M,0,−M,1,−M,1,M,1,−M,0,−M,1,M,1,−M,1,−M}*(1+j)/sqrt(2)

EHT-STF(−8)=0,EHT-STF(8)=0,

EHT-STF(−1016)=0,EHT-STF(1016)=0  <Equation 10>

In the EHT-STF for an 80+80 MHz PPDU, a sequence for a lower 80 MHz maybe the same as Equation 9. And, in the EHT-STF for the 80+80 MHz PPDU, asequence for a higher 80 MHz may be configured based on the followingequation.

EHT-STF(−504:8:504)={−M, 1, −M, 1, M, 1, −M, 0, −M, 1,M,1,−M,1,−M}*(1+j)/sqrt(2)

EHT-STF(−504)=0,

EHT-STF(504)=0  <Equation 11>

An EHT-LTF may have first, second, and third types (i.e., 1×, 2×,4×LTF). For example, the first/second/third type LTF may be generatedbased on an LTF sequence in which non-zero coefficients are positionedat 4/2/1 subcarrier spacing(s). The first/second/third type LTF may havea time length of 3.2/6.4/12.8 μs. Additionally, various lengths of GI(e.g., 0.8/1/6/3.2 μs) may be applied to the first/second/third typeLTF.

Information related to an STF and/or LTF type (including informationrelated to GI that is applied to the LTF) may be included in an SIG Afield and/or SIG B field of FIG. 18 .

The PPDU (i.e., EHT-PPDU) of FIG. 18 may be configured based on examplesof FIG. 5 and FIG. 6 .

For example, an EHT PPDU being transmitted over a 20 MHz band, i.e., a20 MHz EHT PPDU, may be configured based on RUs of FIG. 5 . That is, thelocation of an RU of the EHT-STF, EHT-LTF, data field being included inthe EHT PPDU may be determined as shown in FIG. 5 .

An EHT PPDU being transmitted over a 40 MHz band, i.e., a 40 MHz EHTPPDU, may be configured based on RUs of FIG. 6 . That is, the locationof an RU of the EHT-STF, EHT-LTF, data field being included in the EHTPPDU may be determined as shown in FIG. 6 .

Since the RU location of FIG. 6 corresponds to 40 MHz, if the pattern ofFIG. 6 is repeated two times, a tone plan for 80 MHz may be determined.That is, an 80 MHz EHT PPDU may be transmitted based on a new tone planin which the RU of FIG. 6 is repeated two times, and not the RU of FIG.7 .

In case the pattern of FIG. 6 is repeated two times, 23 tones (i.e., 11guard tones+12 guard tones) may be configured in a DC region. That is, atone plan for an 80 MHz EHT PPDU being allocated based on OFDMA may have23 DC tones. On the other hand, an 80 MHz EHT PPDU being allocated basedon non-OFDMA (i.e., non-OFDMA full Bandwidth 80 MHz PPDU) may beconfigured based on 996 RUs and may include 5 DC tones, 12 left-guardtones, and 11 right-guard tones.

Atone plan for 160/240/320 MHz may be configured to have a format ofrepeating the pattern of FIG. 6 multiple times.

The PPDU of FIG. 18 may be determined (or identified) as an EHT PPDUbased on the following method.

A receiving STA may determine a type of an RX PPDU as the EHT PPDU,based on the following aspect. For example, the RX PPDU may bedetermined as the EHT PPDU: 1) when a first symbol after an L-LTF signalof the RX PPDU is a BPSK symbol; 2) when RL-SIG in which the L-SIG ofthe RX PPDU is repeated is detected; and 3) when a result of applying“module 3” to a value of a length field of the L-SIG of the RX PPDU isdetected as “0”. When the RX PPDU is determined as the EHT PPDU, thereceiving STA may detect a type of the EHT PPDU (e.g., anSU/MU/Trigger-based/Extended Range type), based on bit informationincluded in a symbol after the RL-SIG of FIG. 18 . In other words, thereceiving STA may determine the RX PPDU as the EHT PPDU, based on: 1) afirst symbol after an L-LTF signal, which is a BPSK symbol; 2) RL-SIGcontiguous to the L-SIG field and identical to L-SIG; 3) L-SIG includinga length field in which a result of applying “modulo 3” is set to “0”;and 4) a 3-bit PHY version identifier of the aforementioned U-SIG (e.g.,a PHY version identifier having a first value).

For example, the receiving STA may determine the type of the RX PPDU asthe EHT PPDU, based on the following aspect. For example, the RX PPDUmay be determined as the HE PPDU: 1) when a first symbol after an L-LTFsignal is a BPSK symbol; 2) when RL-SIG in which the L-SIG is repeatedis detected; and 3) when a result of applying “module 3” to a value of alength field of the L-SIG is detected as “1” or “2”.

For example, the receiving STA may determine the type of the RX PPDU asa non-HT, HT, and VHT PPDU, based on the following aspect. For example,the RX PPDU may be determined as the non-HT, HT, and VHT PPDU: 1) when afirst symbol after an L-LTF signal is a BPSK symbol; and 2) when RL-SIGin which L-SIG is repeated is not detected. In addition, even if thereceiving STA detects that the RL-SIG is repeated, when a result ofapplying “modulo 3” to the length value of the L-SIG is detected as “0”,the RX PPDU may be determined as the non-HT, HT, and VHT PPDU.

In the following example, a signal represented as a (TX/RX/UL/DL)signal, a (TX/RX/UL/DL) frame, a (TX/RX/UL/DL) packet, a (TX/RX/UL/DL)data unit, (TX/RX/UL/DL) data, or the like may be a signaltransmitted/received based on the PPDU of FIG. 18 . The PPDU of FIG. 18may be used to transmit/receive frames of various types. For example,the PPDU of FIG. 18 may be used for a control frame. An example of thecontrol frame may include a request to send (RTS), a clear to send(CTS), a power save-poll (PS-poll), BlockACKReq, BlockAck, a null datapacket (NDP) announcement, and a trigger frame. For example, the PPDU ofFIG. 18 may be used for a management frame. An example of the managementframe may include a beacon frame, a (re-)association request frame, a(re-)association response frame, a probe request frame, and a proberesponse frame. For example, the PPDU of FIG. 18 may be used for a dataframe. For example, the PPDU of FIG. 18 may be used to simultaneouslytransmit at least two or more of the control frame, the managementframe, and the data frame.

1. Tone Plan in 802.11Ax WLAN System

In the present specification, a tone plan relates to a rule fordetermining a size of a resource unit (RU) and/or a location of the RU.Hereinafter, a PPDU based on the IEEE 802.11ax standard, that is, a toneplan applied to an HE PPDU, will be described. In other words,hereinafter, the RU size and RU location applied to the HE PPDU aredescribed, and control information related to the RU applied to the HEPPDU is described.

In the present specification, control information related to an RU (orcontrol information related to a tone plan) may include a size andlocation of the RU, information of a user STA allocated to a specificRU, a frequency bandwidth for a PPDU in which the RU is included, and/orcontrol information on a modulation scheme applied to the specific RU.The control information related to the RU may be included in an SIGfield. For example, in the IEEE 802.11ax standard, the controlinformation related to the RU is included in an HE-SIG-B field. That is,in a process of generating a TX PPDU, a transmitting STA may allow thecontrol information on the RU included in the PPDU to be included in theHE-SIG-B field. In addition, a receiving STA may receive an HE-SIG-Bincluded in an RX PPDU and obtain control information included in theHE-SIG-B, so as to determine whether there is an RU allocated to thereceiving STA and decode the allocated RU, based on the HE-SIG-B.

In the IEEE 802.11ax standard, HE-STF, HE-LTF, and data fields may beconfigured in unit of RUs. That is, when a first RU for a firstreceiving STA is configured, STF/LTF/data fields for the first receivingSTA may be transmitted/received through the first RU.

In the IEEE 802.11ax standard, a PPDU (i.e., SU PPDU) for one receivingSTA and a PPDU (i.e., MU PPDU) for a plurality of receiving STAs areseparately defined, and respective tone plans are separately defined.Specific details will be described below.

The RU defined in 11ax may include a plurality of subcarriers. Forexample, when the RU includes N subcarriers, it may be expressed by anN-tone RU or N RUs. A location of a specific RU may be expressed by asubcarrier index. The subcarrier index may be defined in unit of asubcarrier frequency spacing. In the 11ax standard, the subcarrierfrequency spacing is 312.5 kHz or 78.125 kHz, and the subcarrierfrequency spacing for the RU is 78.125 kHz. That is, a subcarrierindex+1 for the RU may mean a location which is more increased by 78.125kHz than a DC tone, and a subcarrier index −1 for the RU may mean alocation which is more decreased by 78.125 kHz than the DC tone. Forexample, when the location of the specific RU is expressed by[−121:−96], the RU may be located in a region from a subcarrier index−121 to a subcarrier index −96. As a result, the RU may include 26subcarriers.

The N-tone RU may include a pre-set pilot tone.

2. Null Subcarrier and Pilot Subcarrier

A subcarrier and resource allocation in the 802.11ax system will bedescribed.

An OFDM symbol consists of subcarriers, and the number of subcarriersmay function as a bandwidth of a PPDU. In the WLAN 802.11 system, a datasubcarrier used for data transmission, a pilot subcarrier used for phaseinformation and parameter tacking, and an unused subcarrier not used fordata transmission and pilot transmission are defined.

An HE MU PPDU which uses OFDMA transmission may be transmitted by mixinga 26-tone RU, a 52-tone RU, a 106-tone RU, a 242-tone RU, a 484-tone RU,and a 996-tone RU.

Herein, the 26-tone RU consists of 24 data subcarriers and 2 pilotsubcarriers. The 52-tone RU consists of 48 data subcarriers and 4 pilotsubcarriers. The 106-tone RU consists of 102 data subcarriers and 4pilot subcarriers. The 242-tone RU consists of 234 data subcarriers and8 pilot subcarriers. The 484-tone RU consists of 468 data subcarriersand 16 pilot subcarriers. The 996-tone RU consists of 980 datasubcarriers and 16 pilot subcarriers.

1) Null Subcarrier

As shown in FIG. 5 to FIG. 7 , a null subcarrier exists between 26-toneRU, 52-tone RU, and 106-tone RU locations. The null subcarrier islocated near a DC or edge tone to protect against transmit centerfrequency leakage, receiver DC offset, and interference from an adjacentRU. The null subcarrier has zero energy. An index of the null subcarrieris listed as follows.

Channel Width RU Size Null Subcarrier Indices 20 MHz 26, 52 ±69, ±122106 none 242 none 40 MHz 26, 52 ±3, ±56, ±57, ±110, ±137, ±190, ±191,±244 106 ±3, ±110, ±137, ±244 242, 484 none 80 MHz 26, 52 ±17, ±70, ±71,±124, ±151, ±204, ±205, ±258, ±259, ±312, ±313, ±366, ±393, ±446, ±447,±500 106 ±17, ±124, ±151, ±258, ±259, ±366, ±393, ±500 242, 484 none 996none 160 MHz  26, 52, 106 {null subcarrier indices in 80 MHz − 512, nullsubcarrier indices in 80 MHz + 512} 242, 484, 996, none 2 × 996

A null subcarrier location for each 80 MHz frequency segment of the80+80 MHz HE PPDU shall follow the location of the 80 MHz HE PPDU.

2) Pilot Subcarrier

If a pilot subcarrier exists in an HE-LTF field of HE SU PPDU, HE MUPPDU, HE ER SU PPDU, or HE TB PPDU, a location of a pilot sequence in anHE-LTF field and data field may be the same as a location of 4×HE-LTF.In 1×HE-LTF, the location of the pilot sequence in HE-LTF is configuredbased on pilot subcarriers for a data field multiplied 4 times. If thepilot subcarrier exists in 2×HE-LTF, the location of the pilotsubcarrier shall be the same as a location of a pilot in a 4×datasymbol. All pilot subcarriers are located at even-numbered indiceslisted below.

Channel Width RU Size Pilot Subcarrier Indices 20 MHz 26, 52 ±10, ±22,±36, ±48, ±62, ±76, ±90, ±102, ±116 106, 242 ±22, ±48, ±90, ±116 40 MHz26, 52 ±10, ±24, ±36, ±50, ±64, ±78, ±90, ±104, ±116, ±130, ±144, ±158,±170, ±184, ±198, ±212, ±224, ±238 106, 242, 484 ±10, ±36, ±78, ±104,±144, ±170, ±212, ±238 80 MHz 26, 52 ±10, ±24, ±38, ±50, ±64, ±78, ±92,±104, ±118, ±130, ±144, ±158, ±172, ±184, ±198, ±212, ±226, ±238, ±252,±266, ±280, ±292, ±306, ±320, ±334, ±346, ±360, ±372, ±386, ±400, ±414,±426, ±440, ±454, ±468, ±480, ±494 106, 242, 484 ±24, ±50, ±92, ±118,±158, ±184, ±226, ±252, ±266, ±292, ±334, ±360, ±400, ±426, ±468, ±494996 ±24, ±92, ±158, ±226, ±266, ±334, ±400, ±468 160 MHz  26, 52, 106,242, {pilot subcarrier indices in 80 MHz − 512, pilot subcarrier indices484 in 80 MHz + 512} 996 {for the lower 80 MHz, pilot subcarrier indicesin 80 MHz − 512, for the upper 80 MHz, pilot subcarrier indices in 80MHz + 512}

At 160 MHz or 80+80 MHz, the location of the pilot subcarrier shall usethe same 80 MHz location for 80 MHz of both sides.

3. HE Transmit Procedure and Low Density Parity Check (LDPC) ToneMapping

In an 802.11ax wireless local area network (WLAN) system, transmissionprocedures (or transmit procedures) in a physical layer (PHY) include aprocedure for an HE Single User (SU) PPDU, a transmission procedure foran HE extended range (ER) SU PPDU, a transmission procedure for an HEMulti User (MU) PPDU, and a transmission procedure for an HEtrigger-based (TB) PPDU. A FORMAT field of aPHY-TXSTART.request(TXVECTOR) may be the same as HE_SU, HE_MU, HE_ER_SUor HE_TB. The transmission procedures do not describe operations ofoptional features, such as Dual Carrier Modulation (DCM). Among thediverse transmission procedures, FIG. 21 shows only the PHY transmissionprocedure for the HE SU PPDU.

FIG. 19 shows an example of a PHY transmission procedure for HE SU PPDU.

In order to transmit data, the MAC generates a PHY-TXSTART.requestprimitive, which causes a PHY entity to enter a transmit state.Additionally, the PHY is configured to operate in an appropriatefrequency via station management through PLME. Other transmissionparameters, such as HE-MCS, coding type, and transmission power areconfigured through a PHY-SAP by using a PHY-TXSTART.request(TXVECTOR)primitive. After transmitting a PPDU that transfers (or communicates) atrigger frame, a MAC sublayer may issue a PHY-TRIGGER.request togetherwith a TRIGVECTOR parameter, which provides information needed fordemodulating an HE TB PPDU response that is expected of the PHY entity.

The PHY indicates statuses of a primary channel and another channel viaPHY-CCA.indication. The transmission of a PPDU should be started by thePHY after receiving the PHY-TXSTART.request(TXVECTOR) primitive.

After a PHY preamble transmission is started, the PHY entity immediatelyinitiates data scrambling and data encoding. An encoding method for thedata field is based on FEC_CODING, CH_BANDWIDTH, NUM_STS, STBC, MCS, andNUM_USERS parameters of the TXVECTOR.

A SERVICE field and a PSDU are encoded in a transmitter (or transmittingdevice) block diagram, which will be described later on. Data should beexchanged between the MAC and the PHY through a PHY-DATA.request(DATA)primitive that is issued by the MAC and PHY-DATA. confirm primitivesthat are issued by the PHY. A PHY padding bit is applied to the PSDU inorder to set a number of bits of the coded PSDU to be an integermultiple of a number of coded bits per OFDM symbol.

The transmission is swiftly (or quickly) ended by the MAC through aPHY-TXEND.request primitive. The PSDU transmission is ended uponreceiving a PHY-TXEND.request primitive. Each PHY-TXEND.requestprimitive mat notify its reception together with a PHY-TXEND.confirmprimitive from the PHY.

A packet extension and/or a signal extension may exist in a PPDU. APHY-TXEND.confirm primitive is generated at an actual end time of a mostrecent PPDU, an end time of a packet extension, and an end time of asignal extension.

In the PHY, a Guard Interval (GI) that is indicated together with a GIduration in a GI_TYPE parameter of the TXVECTOR is inserted in all dataOFDM symbols as a solution for a delay spread.

If the PPDU transmission is completed, the PHY entity enters a receivestate.

FIG. 20 shows an example of a block diagram of a transmitting device forgenerating each field of an HE PPDU.

In order to generate each field of the HE PPDU, the following blockdiagrams are used.

-   -   a) pre-FEC PHY padding    -   b) Scrambler    -   c) FEC (BCC or LDPC) encoders    -   d) post-FEC PHY padding    -   e) Stream parser    -   f) Segment parser (for contiguous 160 MHz and non-contiguous        80+80 MHz transmission)    -   g) BCC interleaver    -   h) Constellation mapper    -   i) DCM tone mapper    -   j) Pilot insertion    -   k) Replication over multiple 20 MHz (for BW>20 MHz)    -   l) Multiplication by 1^(st) column of PHE-LTF    -   m) LDPC tone mapper    -   n) Segment deparser    -   o) Space time block code (STBC) encoder for one spatial stream    -   p) Cyclic shift diversity (CSD) per STS insertion    -   q) Spatial mapper    -   r) Frequency mapping    -   s) Inverse discrete Fourier transform (IDFT)    -   f) Cyclic shift diversity (CSD) per chain insertion    -   u) Guard interval (GI) insertion    -   v) Windowing

FIG. 20 shows a block diagram of a transmitting device (or transmitterblock diagram) that is used for generating a data field of an HE SingleUser (SU) PPDU having LDPC encoding applied thereto and beingtransmitted at a 160 MHz. If the transmitter block diagram is used forgenerating a data field of an HE SU PPDU that is transmitted in an 80+80MHz band, a segment deparser is not used as shown in FIG. 22 . That is,the block diagram of the transmitter (or transmitting device) is usedper 80 MHz band in a situation where the band is divided into an 80 MHzband and another 80 MHz band by using a segment parser.

Data fields of an HE SU PPDU, an HE extended range (ER) SU PPDU, and anHE trigger-based (TB) PPDU may be configured as described below via LDPCencoding.

-   -   a) Construct the SERVICE field as described in 28.3.11.3        (SERVICE field) and append the PSDU to the SERVICE field.    -   b) Pre-FEC padding: Append the pre-FEC padding bits as described        in 28.3.11 (Data field). There are no tail bits.    -   c) Scrambler: Scramble the pre-FEC padded data.    -   d) LDPC encoder: LDPC encode as described in 28.3.11.5.2 (LDPC        coding).    -   e) Post-FEC padding: Append the post-FEC pad bits and Packet        Extension field as described in 28.3.11 (Data field).    -   f) Stream parser: Rearrange the output of LDPC encoder into        blocks as described in 28.3.11.6 (Stream parser).    -   g) Segment parser (ifneeded): In a 160 MHz or 80+80 MHz        transmission with a 2×996-tone RU, divide the output of each        stream parser into two frequency subblocks as described in        28.3.11.6 (Stream parser). This block is bypassed for |2.0 MHz,        40 MHz, and 80 MHz transmissions.    -   h) Constellation. snapper: Map to BPSK, BPSK DCM, QPSK, QPSK        DCM, 16-QAM, 16-QAM DCM, 64-QAM, 2.56-QAM, or 1024-QAM        constellation points as described in 28.3.11.9 (Constellation        snapping).    -   i) LDPC tone mapper: the LDPC tone mapping shall be performed on        all LDPC encoded streams as described in 2.8.3.11.11 (LDPC tone        mapper).    -   j) Segment deparser (if needed): In 160 MHz transmission, merge        the two frequency subblocks into one frequency segment as        described in 28.3.11.12 (Segment. &parser). This block is        bypassed for 2.0 MHz, 40 MHz, 80 MHz, and 80+80 MHz        transmissions.    -   k) STBC: Apply STBC as described in 28.3.11.10 (Space-time block        coding).    -   l) Pilot insertion: Insert pilots following the steps described        in 28.3.11.13 (Pilot subcarriers).    -   m) CSD: Apply CSD for each space-time stream and frequency        segment as described in 28.3.10.2.2 (Cyclic shift for HE        modulated fields).    -   n) Spatial mapping: Apply the Q matrix as described in        28.3.11.14 (OFDM modulation).    -   o) IDFT: In an 80+80 MHz transmission, map each frequency        subblock to a separate IDFT. Compute the inverse discrete        Fourier transform.    -   p) Insert GI and apply windowing.: Prepend a GI determined by        the TXVECTOR parameter GI_TYPE and apply windowing as described        in 28.3.9 Mathematical description of signals).    -   q) Analog and RF: Upconvert the resulting complex baseband        waveform with each transmit chain to an RF signal according to        the center frequency of the desired channel and transmit. Refer        to 28.3.9 (Mathematical description of signals) and 28.3.10 (HE        preamble) for details.

Referring to FIG. 20 , a data field (or data bit sequence) may beencoded in an LDPC encoder. A data bit sequence that is inputted to theLDPC encoder may be in a scrambled state by a scrambler.

The encoded data bit sequence that is encoded by the LDPC encoder isdivided into multiple spatial streams by a stream parser. At this point,an encoded data bit sequence that is divided into each spatial streammay be referred to as a spatial block. A number of the spatial blocksmay be determined by a number of spatial streams that are used fortransmitting an PPDU, and the number of spatial blocks may be set to beequal to the number of spatial blocks.

Each spatial block is divided into at least one or more data segments bythe segment parser. As shown in FIG. 22 , when a data field istransmitted in a 160 MHz band, the 160 MHz band is divided into two 80MHz bands, and the spatial block is divided into a first data segmentand a second data segment for each 80 MHz band. Thereafter, the firstand second data segments may each be processed with constellationmapping and LDPC mapping for each 80 MHz band.

In an HE MU transmission, except for cyclic shift diversity (CSD) beingperformed based on knowledge of a corresponding user on a space-timestream start index, a PPDU encoding processor is independently performedin a resource unit (RU) per user up to the input of a spatial mappingblock. All user data of the RU is coupled with a transmit chain of aspatial mapping block and then mapped.

Hereinafter, LDPC tone mapping will be described.

LDPC tone mapping should be performed in all LDPC-coded streams by usingan LDPC tone mapping distance parameter D_(TM). D_(TM) is a constant foreach bandwidth and is given a value for each band, as shown below. LDPCtone mapping should not be performed for an encoded stream by using BCC.

160 MHz, Parameter 20 MHz 40 MHz 80 MHz 80 + 80 MHz D_(TM) 4 6 9 9

For a VHT PPDU transmission, LDPC tone mapping for an LDPC-coded streamrelated to a user u may be performed, as shown below, by substituting astream of complex numbers generated by a constellation mapper.

d″ _(t(k),i,n,l,u) =d′ _(k,i,n,l,u);

-   -   k=0, 1, . . . , N_(SD)−1 for 20 MHz, 40 MHz, 80 MHz 80+80 MHz;    -   k=0, 1, . . . , N_(SD)/2-1 for 160 MHz:    -   i=1, . . . , N_(SS,u);    -   n=0, 1, . . . , N_(SYM)−1;    -   l=0 far 20 MHz, 40 MHz, and 80 MHz;    -   l=0, 1 for 160 MHz and 80+80 MHz;    -   u=0, . . . , N_(user)−1    -   where

t(k)={D _(TM)(k mod N _(SD) /D _(TM))+[k*D _(TM) /N _(SD)], for 20 MHz,40 MHz, 80 MHz, and 80+80 MHz {D _(TM)(k mod(N _(SD)/2)/D _(TM))+[k*D_(TM)/(N _(SD)/2)], for 160 MHz

As a result of the LDPC tone mapping operation, each of twoconsecutively generated complex constellation numbers and d′_(k,i,n,l,u)and d′_(k+1,i,n,l,u) may be transmitted from two data tones,respectively, each data tone being spaced apart by at least D_(TM)−1.For example, d′_(k,i,n,l,u) may be transmitted from a first data tone,d′_(k+1,i,n,l,u) may be transmitted from a second data tone, and thefirst data tone and the second data tone may be spaced apart byD_(TM)−1. The aforementioned operation is the same as performingblock-interleaving on complex numbers d′_(0,i,n,l,u), . . . ,d′_(NSD−1,i,n,l,u) for variables i, n, and u by using a matrix having aD_(TM) row and a N_(SD)/D_(TM) column (for 20 MHz, 40 MHz, 80 MHz or80+80 MHz) or N_(SD)/2*D_(TM) column (for 160 MHz). At this point,d′_(0,i,n,l,u), . . . , d′_(NSD−1,i,n,l,u) are written row-wise in thematrix, and d′_(0,i,n,l,u), . . . , d′_(NSD−1,i,n,l,u) are readcolumn-wise from the matrix.

LDPC tone mapping is separately performed for an upper 80 MHz and alower 80 MHz of a 160 MHz or 80+80 MHz transmission that is indicated byfrequency subblock index 1.

Since LDPC tone mapping is not performed for a BCC-coded stream, thefollowing equation may be applied to the BCC-coded stream.

d″ _(k,i,n,l,u) =d′ _(k,i,n,l,u);

-   -   k=0, 1, . . . , N_(SD)−1 for 20 MHz, 40 MHz, 80 MHz 80+80 MHz;    -   k=0, 1, . . . , N_(SD)/2-1 for 160 MHz:    -   i=1, . . . , N_(SS,u);    -   n=0, 1, . . . , N_(SYM)−1;    -   l=0 far 20 MHz, 40 MHz, and 80 MHz;    -   l=0, 1 for 160 MHz and 80+80 MHz;    -   u=0, . . . , N_(user)−1

Additionally, LDPC tone mapping should be performed in all LDPC-codedstreams that are mapped to a resource unit (RU). LDPC tone mappingshould not be performed on a stream having used BCC. When DCM is appliedto an LDPC-coded stream, D_(TM_DCM) should be applied to both a lowerhalf data subcarrier of the RU and an upper half data subcarrier of theRU. LDPC tone mapping distance parameters D_(TM) and D_(TM_DCM) areconstant values for each of an RU size and another RU size,

RU Size (tones) Parameter 26 52 106 242 484 996 2 × 996 D_(TM) 1 3 6 912 20 20 D_(TM) _(—) _(DCM) 1 1 3 9 9 14 14

LDPC tone mapping distance parameters D_(TM) and D_(TM_DCM) are appliedto a frequency subblock l=0 and frequency subblock l=1, respectively.

For an HE PPDU without DCM, in an r-th RU, LDPC tone mapping for anLDPC-coded stream related to a user u may be performed, as shown below,by substituting a stream of complex numbers generated by a constellationmapper.

${d_{{t(k)},i,n,l,r,u}^{''}d_{k,i,n,l,r,u}^{\prime}}{where}{k = \left\{ {{{\begin{matrix}\begin{matrix}{0,1,\ldots,{N_{SD} - {1{for}a}}} \\{{26 -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}}\end{matrix} \\{0,1,\ldots,{{N_{SD}/2} - {1{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix}i} = 1},\ldots,{{N_{{SS},r,u}n} = 0},1,\ldots,{{N_{SYM} - {1l}} = \left\{ {{{\begin{matrix}{{{0{for}a26} -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}} \\{0,{{1{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix}u} = 0},\ldots,{{N_{{user},r} - {1r}} = 0},\ldots,{N_{RU} - 1}} \right.}} \right.}$

N_(SD) is the number of data tones in the r-th RU

${t(k)} = \left\{ \begin{matrix}\begin{matrix}{{{D_{TM}\left( {k{mod}\frac{N_{SD}}{D_{TM}}} \right)} + \left\lfloor \frac{k \cdot D_{TM}}{N_{SD}} \right\rfloor},} \\{{{{for}a26} -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}}\end{matrix} \\{{{D_{TM}\left( {k{mod}\frac{N_{SD}/2}{D_{TM}}} \right)} + \left\lfloor \frac{k \cdot D_{TM}}{N_{SD}/2} \right\rfloor},{{{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix} \right.$

For an HE PPDU having DCM applied in a Data field, in an r-th RU, LDPCtone mapping for an LDPC-coded stream related to a user u may beperformed, as shown below, by substituting a stream of complex numbersgenerated by a constellation mapper.

${d_{{t(k)},i,,l,r,u}^{''} = d_{k,i,n,l,r,u}^{\prime}}{where}{k = \left\{ {{{\begin{matrix}\begin{matrix}{0,1,\ldots,{{2N_{SD}} - {1{for}a}}} \\{{26 -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}}\end{matrix} \\{0,1,\ldots,{N_{SD} - {1{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix}i} = 1},\ldots,{{N_{{SS},r,u}n} = 0},1,\ldots,{{N_{SYM} - {1l}} = \left\{ {{{\begin{matrix}{{{0{for}a26} -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}} \\{0,{{1{for}a \times 996} - {{tone}{RL}}}}\end{matrix}u} = 0},\ldots,{{N_{{user},r} - {1r}} = 0},\ldots,{N_{RU} - 1}} \right.}} \right.}$

-   -   N_(SD) is the number of data tones in the r-th RU when DCM is        applied    -   For a 26-, 52-, 106-, 242-, 484- and 996-tone RU,

${t(k)} = \left\{ \begin{matrix}{{{D_{{TM}\_{DCM}}\left( {k{mod}\frac{N_{SD}}{D_{{TM}\_{DCM}}}} \right)} + \left\lfloor \frac{k \cdot D_{{TM}\_{DCM}}}{N_{SD}} \right\rfloor},{{{for}k} < N_{SD}}} \\\begin{matrix}{{{D_{{TM}\_{DCM}}\left( {\left( {k - N_{SD}} \right){mod}\frac{N_{SD}}{D_{{TM}\_{DCM}}}} \right)} + \left\lfloor \frac{\left( {k - N_{SD}} \right) \cdot D_{{TM}\_{DCM}}}{N_{SD}} \right\rfloor + N_{SD}},} \\{{{for}k} \geq N_{SD}}\end{matrix}\end{matrix} \right.$

-   -   For a 2×996-tone RU,

${t(k)} = \left\{ \begin{matrix}{{{D_{{TM}\_{DCM}}\left( {k{mod}\frac{N_{SD}/2}{D_{{TM}\_{DCM}}}} \right)} + \left\lfloor \frac{k \cdot D_{{TM}\_{DCM}}}{N_{SD}/2} \right\rfloor},{{{for}0} \leq k < {{N_{SD}/2} - 1}}} \\\begin{matrix}{{D_{{TM}\_{DCM}}\left( {\left( {k - {N_{SD}/2}} \right){mod}\frac{N_{SD}/2}{D_{{TM}\_{DCM}}}} \right)} + \left\lfloor \frac{\left( {k - {N_{SD}/2}} \right) \cdot D_{{TM}\_{DCM}}}{N_{SD}/2} \right\rfloor +} \\{{N_{SD}/2},{{{for}N_{SD}/2} \leq \leq {N_{SD} - 1}}}\end{matrix}\end{matrix} \right.$

-   -   D_(TM_DCM) the LDPC tone mapping distance for the r-th RU when        DCM is applied.

An LDPC tone mapper for a 26-, 52-, 106-, 242-, 484- and 996-tone isdefined as one segment. LDPC tone mapping is separately performed forupper 80 MHz and lower 80 MHz frequency segments of a 2×996-tone RU thatis indicated by frequency subblock index 1.

Since LDPC tone mapping is not performed for a BCC-coded stream, thefollowing equation may be applied to the BCC-coded stream.

${d_{k,i,n,l,r,u}^{''} = d_{k,i,n,l,r,u}^{\prime}}{where}{k = \left\{ {{{\begin{matrix}\begin{matrix}{0,1,\ldots,{N_{SD} - {1{for}a}}} \\{{26 -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}}\end{matrix} \\{0,1,\ldots,{{N_{SD}/2} - {1{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix}i} = 1},\ldots,{{N_{{SS},r,u}n} = 0},1,\ldots,{{N_{SYM} - {1l}} = \left\{ {{{\begin{matrix}{{{0{for}a26} -},{52 -},{106 -},{242 -},{484 - {{and}996} - {{tone}{RU}}}} \\{0,{{1{for}a2 \times 996} - {{tone}{RU}}}}\end{matrix}u} = 0},\ldots,{{N_{{user},r} - {1r}} = 0},\ldots,{N_{RU} - 1}} \right.}} \right.}$

A brief description of the concept of LDPC tone mapping, which isdescribed in the present specification, is as follows.

When data rate of a related art WLAN data packet increases, a length ofan LDPC codeword (LCW) may become shorter than N_CBPS (a number of bitswithin an OFDM symbol). In this case, an LDPC-coded bit is transmittedto some tones or subcarriers. And, accordingly, a problem of failing toensure sufficient frequency diversity may occur.

FIG. 21 shows an example of an LDPC tone mapping operation.

In the present specification, LDPC tone mapping may mean a mappingscheme for mapping an LDPC-coded stream at an interval (or spacing) of aspecific tone or subcarrier. The present specification describes anexample of setting tone spacing (D_TM) to 4, 6, 9, and so on, inaccordance with a bandwidth (BW) of a PPDU. For example, FIG. 23 is anexample of LDPC tone mapping having tone spacing (D_TM) set to 3. Thatis, an operation that is similar to an interleaving operation may beperformed through the LDPC tone mapping.

For example, for a data field of a PPDU of the 802.11ac standard (i.e.,VHT PPDU) or a PPDU of the 802.11ax standard (i.e., HE PPDU), the LDPCtone mapper may be positioned after the Constellation mapper. Forexample, in FIG. 22 , an output of the Constellation mapper (i.e.,contiguous Constellation symbols) may be mapped to a data tone that isseparated at a spacing (or interval) of D_TM−1.

FIG. 22 shows an example of a DCM method being applied to data.

Meanwhile, in IEEE 802.11ax, a Dual Carrier/Sub-carrier Modulation (DCM)scheme is applied. A transmitting device (or transmitter) that is basedon the DCM scheme may transmit the same information to differentsubcarriers. For example, the transmitting device may include astructure that is shown in FIG. 22 . As shown in FIG. 22 , first datainformation may be included in subcarrier K based on a firstconstellation mapping, i.e., modulation mapping 1. Additionally, thesame first data information may be included in subcarrier K+N/2 based ona second constellation mapping, i.e., modulation mapping 2. The firstconstellation mapping and the second constellation mapping may be thesame mapping scheme or may each be a different mapping scheme. In FIG.22 , variable N may also be N_SD, which is a number of data tones beingincluded in an RU or frequency segment. Additionally, although thescheme of FIG. 24 is an example of a result of first/secondconstellation mappings that are applied to the same data being mapped tofirst/second tones, for example, it is possible for a result offirst/second/third constellation mappings that are applied to the samedata to be mapped to first/second/third tones, or it is possible for aresult of first/second/ . . . /N-th constellation mappings that areapplied to the same data to be mapped to first/second/ . . . /N-thtones.

The DCM scheme may be applied only to a data field and/or SIG-B field ofan HE PPDU. Additionally, the DCM scheme may be used or may not be usedin the transmitting device (optional feature).

A more detailed description of the DCM scheme of 11 ax is as follows.

DCM is an optional modulation scheme for HE-SIG-B and data fields. DCMmay be applied to an HE_SU PPDU and an HE_ER_SU PPDU. In an HE_MU PPDUor HE_TB PPDU, DCM may be applied to an RU that includes data for oneuser and cannot be applied to an RU that includes data for multipleusers.

DCM is applicable only for HE-MCS 0, 1, 3, and 4. DCM is applicable onlyfor Nss=1 or Nss=2 (In case of a single user RU in an HE_MU PPDU,Nss,r,u=1 or Nss,r,u=2). DCM is not applicable together with MU-MIMO orSTBC.

When DCM is used, a bit sequence is mapped to one symbol pair (d′_(k),d′_(q(k))). In order to use a frequency diversity for a 996-tone RU or asmaller RU, k has a range of 0<=k<=N_(SD)−1, and q(k) has a range ofN_(SD)<=q(k)<=2N_(SD)−1. For a 2×996-tone RU, k has a range of0<=k<=N_(SD)/2−1, and q(k) has a range of N_(SD)/2<=q(k)<=N_(SD)−1. Inorder to maximize the frequency diversity, an index of a DCM subcarrierpair (k, q(k)) is q(k)=k+N_(SD) for a 996-tone RU or a smaller RU, andq(k)=k+N_(SD)/2 for a 2×996-tone RU. Herein, when DCM=1, N_(SD) is givena value of N_(SD). And, when DCM=0, N_(SD) is given a half value ofN_(SD).

A modulation bit having DCM applied thereto may be described as follows.

-   -   For BPSK modulation with DCM, the input stream is broken into        groups of N_(CBPS) or N_(CBPS,u) bits (B₀, B₁, B_(N) _(CBPS,u)        ⁻¹). Each bit Bk is BPSK modulated to a sample dk. This        generates the samples for the lower half of the data        subcarriers. For the upper half of the subcarriers, the samples        are generated as d_(k+NSD)=d_(k)×e^(j(k+N) ^(SD) ^()π), k=0, 1,        . . . , N_(SD)−1. The N_(SD) here refers to the N_(SD) with        DCM=1, which is half the value of N_(SD) with DCM=0.    -   For QPSK modulation with DCM, the input stream is broken into        groups of N_(CBPS) or N_(CBPS,u) bits (B₀, B₁, . . . , B_(N)        _(CBPS,u) ⁻¹). Each pair of bits (B_(2k), B_(2k+1)) is QPSK        modulated to a symbol d_(k). This generates the constellation        points for the lower half the data subcarriers in the RU. For        the upper half of the data sub-carriers in the RU, d_(k+N) _(SD)        =conj(d_(k)), where conj( ) represents the complex conjugate        operation. The N_(SD) here refers to the N_(SD) with DCM=1,        which is half the value of N_(SD) with DCM=0.    -   For 16-QAM modulation with DCM, the input stream is broken into        groups of N_(CBPS) or B_(CBPS,u) bits (B₀, B1, . . . , B_(N)        _(CBPS,u) ⁻¹). A group of 4 bits (B_(4k), B_(4k+1), B_(4k+2),        B_(4k+3)) is 16-QAM modulated to a sample d_(k) as described in        17.3.5.8 (Subcarrier modulation mapping). This is the sample on        subcarrier k in the lower half In the upper half, the sample        d_(k+N) _(SD) on subcarrier k−N_(SD) is obtained by 16-QAM        modulating a per-mutation of the bits (B_(4k), B_(4k+1),        B_(4k+2), B_(4k+3)). Specifically, d_(k+N) _(SD) is obtained by        applying the 16-QAM modulation procedure in 18.3.5.8 to the bit        group (B_(4k+1), B_(4k), B_(4k+3), B_(4k+2)). The N_(SD) here        refers to the N_(SD) with DCM=1, which is half the value of        N_(SD) with DCM=0.

In a non-OFDMA HE PPDU, a subcarrier allocation related variable for anHE-modulated field may be defined as a tone allocation related parameterfor the non-OFDMA HE PPDU, as shown below.

Parameter CBW20 CBW40 CBW80 CBW80 + 80 CBW160 Description N_(SD) 234 468980 980 1960 Number of data subcarriers per frequency segment N_(SP) 816 16 16 32 Number of pilot subcarriers per frequency segment N_(ST) 242484 996 996 1992 Total number of subcarriers per frequency segmentN_(SR) 122 244 500 500 1012 Highest data subcarrier index per frequencysegment N_(Seg) 1 1 1 2 1 Number of frequency segments N_(DC) 3 5 5 5 23Number of null subcarriers at DC per segment N_(Guard, Left) 6 12 12 1212 Number of low frequency guard subcarriers N_(Guard, Right) 5 11 11 1111 Number of high frequency guard subcarriers NOTE: N_(ST) = N_(SD) +N_(SP)

In an OFDMA HE PPDU, a subcarrier allocation related variable for anHE-modulated field may be defined as a tone allocation related parameterfor the OFDMA HE PPDU, as shown below.

RU Size (subcarriers) Parameter 26 52 106 242 484 996 2 × 996Description N_(SD) 24 48 102 234 468 980 1960 Number of data subcarriersper RU N_(SP) 2 4 4 8 16 16 32 Number of pilot subcarriers per RU N_(ST)26 52 106 242 484 996 1992 Total number of subcarriers per RU NOTE:N_(ST) = N_(SD) + N_(SP)

As described above, N_(SD) may denote a number of data tones beingincluded in one RU or frequency segment (e.g., 20/40/80/160 MHzsegment).

Parameters that are frequently used in an 802.11ax WLAN system may bedefined as follows.

Symbol Explanation N_(RU) For pre-HE modulated fields, N_(RU) = 1. ForHE modulated fields, N_(RU) represents the number of occupied RUs in thetransmission. N_(user,r) For pre-HE modulated fields, N_(user,r) = 1.For HE modulated fields, N_(user,r) represents the total number of usersin the r-th occupied RU of the transmission. N_(user,total) Total numberof users in all occupied RUs of an HE transmission, i.e.,$N_{{user},{total}} = {\sum\limits_{r = 0}^{N_{RU} - 1}N_{{user},r}}$N_(CBPS), N_(CBPS,u) Number of coded bits per symbol for user u, u = 0,. . . , N_(user,total) − 1 For an HE SU PPDU, N_(CBPS) = N_(CBPS,0) Foran HE MU PPDU, N_(CBPS) is undefined N_(CBPSS), N_(CBPSS,u) Number ofcoded bits per symbol per spatial stream for user u, u = 0, . . . ,N_(user,total) − 1. For the Data field of an HE SU PPDU, N_(CBPSS) =N_(CBPSS,0) For the Data field of an HE MU PPDU, N_(CBPSS) is undefinedN_(DBPS), N_(DBPS,u) Number of data bits per symbol for user u, u = 0, .. . , N_(user,total) − 1. For an HE SU PPDU, N_(DBPS) = N_(DBPS,0) Foran HE MU PPDU, N_(DBPS) is undefined

Hereinafter, operations having LDPC tone mapping performed therein willbe described in detail.

FIG. 23 shows an example of LDPC tone mapping having tone spacing set to3 in a 52-tone RU in a situation where DCM is not applied.

FIG. 23 shows an example of LDPC tone mapping being performed withoutDCM for a 52-tone RU. According to the description presented above, k isa constellation mapped tone index that is outputted from theconstellation mapper, and t(k) is an LDPC tone mapped tone index that isoutputted from the LDPC tone mapper. According to the table that ispresented above, D_(TM)=3 and N_(SD)=48 for the 52-tone RU.

A complex constellation number d′_(k,i,n,l,u) that is outputted from theconstellation mapper may obtain a complex constellation numberd″_(t(k),i,n,l,r,u) that is outputted via LDPC tone mapping, which issimilar to the interleaving operation. Thus, it may be known that thed′_(k,i,n,l,r,u) along with d″_(t(k),i,n,l,r,u) is mapped in data tonesthat are spaced apart by D_(TM)−1. That is, as a result of the LDPC tonemapping operation, each of the two serially (or consecutively) generatedcomplex constellation numbers may be transmitted from two data toneseach being spaced apart by D_(TM)−1, respectively.

Referring to FIG. 23 , since LDPC tone mapping for a 52-tone RU isperformed, and since k=0, 1, . . . , 47 and l=0, a segment parser is notperformed. And, since t(k)=D_(TM)*(k modN_(SD)/D_(TM))+[k*D_(TM)/N_(SD)] for the 52-tone RU, the tone index maybe separated by a spacing (or interval) of D_(TM)−1, as shown below.

k=0−>t(k)=0

k=1−>t(k)=3

k=2−>t(k)=6

. . .

k=15−>t(k)=45

k=16−>t(k)=1(return back up and restart interleaving from k=16)

k=17−>t(k)=4

k=18−>t(k)=7

. . .

k=46−>t(k)=44

k=47−>t(k)=47

FIG. 24 shows an example of LDPC tone mapping having tone spacing set to3 in a 106-tone RU in a situation where DCM is applied.

FIG. 24 shows an example of LDPC tone mapping being performed byapplying DCM for a 106-tone RU. According to the description presentedabove, k is a constellation mapped tone index that is outputted from theconstellation mapper, and t(k) is an LDPC tone mapped tone index that isoutputted from the LDPC tone mapper. According to the table that ispresented above, D_(TM_DCM)=3 and N_(SD)=51 for the 106-tone RU.

A complex constellation number d′_(k,i,n,l,r,u) that is outputted fromthe constellation mapper may obtain a complex constellation numberd″_(k,i,n,l,r,u) that is outputted via LDPC tone mapping, which issimilar to the interleaving operation. Thus, it may be known that thed′_(k,i,n,l,r,u) along with d″_(k,i,n,l,r,u) is mapped in data tonesthat are spaced apart by D_(TM)−1. That is, as a result of the LDPC tonemapping operation, each of the two serially (or consecutively) generatedcomplex constellation numbers may be transmitted from two data toneseach being spaced apart by D_(TM)−1, respectively.

Referring to FIG. 24 , since LDPC tone mapping for a 106-tone RU isperformed, and since k=0,1, . . . , 101 and 1=0, a segment parser is notperformed. However, since DCM is applied in this case, when k<N_(SD)(lower half data subcarrier) for the 106-tone RU, sincet(k)=D_(TM_DCM)*(k mod N_(SD)/D_(TM_DCM))+[k*D_(TM_DCM)/N_(SD)], and,when k>=N_(SD) (upper half data subcarrier), sincet(k)=D_(TM_DCM)*((k−N_(SD)) modN_(SD)/D_(TM_DCM))+[(k−N_(SD))*D_(TM_DCM)/N_(SD)], the tone index may beseparated by a spacing (or interval) of D_(TM)−1 per lower half datasubcarrier and upper half data subcarrier, as shown below.

<Lower Half Data Subcarrier>

k=0−>t(k)=0

k=1−>t(k)=3

k=2−>t(k)=6

. . .

k=16−>t(k)=48

k=17−>t(k)=1 (return back up and restart interleaving from k=17)

. . .

k=50−>t(k)=50

<Upper Half Data Subcarrier>

k=51−>t(k)=51

k=52−>t(k)=54

. . .

k=101−>t(k)=101

4. Embodiment(s) Applicable to the Present Specification

In a WLAN 802.11 system, in order to increase peak throughput,transmission of an increased number of streams by using a wider band ora larger number of antennas as compared to the legacy flax is beingconsidered. Additionally, the present specification also considers amethod of using various bands by performing aggregation.

The present specification proposed a tone mapping scheme when LDPCchannel coding is applied in a situation where a PPDU is transmitted byusing a wide band.

In the legacy 802.11ax, data may be transmitted by using a26/52/106/242/484/996/2×996-tone RU. And, in this case, BCC or LDPC maybe used as channel coding. Most particularly, when LDPC is used, LDPCtone mapping may be used for frequency diversity, and a PPDU encodingprocess of a case where LDPC is applied and LDPC tone mapping aredescribed in detail in FIG. 21 to FIG. 26 .

In 802.11be, in addition to the existing (or legacy) RU, a new RUcorresponding to a full band of 240 MHz/320 MHz may be defined, and theexisting RU may use the LDPC tone mapping defined in the legacy 11ax asit is. In case of the new RU, an RU that is configured by repeating thelegacy 80 MHz tone plan or an RU that is designed according to a newmethod may be considered. And, the LDPC tone mapping of the RUs designedaccording to each method may be defined as described below.

4.1. Situation where the Legacy 80 MHz Tone Plan is Repeated

In 240 MHz, a 3×996-tone RU may be additionally used, and, in 320 MHz, a4×996-tone RU may be additionally used. In the corresponding RU,parameters that are used in the legacy 996RU are used as they are.Hereinafter, D_(TM) (i.e., D_(TM)) may denote a tone spacing that isused in the LDPC tone mapping, D_(TM_DCM) may represent a D_(TM) valueof a case where the DCM scheme is applied, and N_(SD)

may denote a number of data tones being included in one RU (or Frequencysegment).

RU size (tones) Parameter 3 × 996 4 × 996 D_(TM) 20 20 D_(TM) _(—)_(DCM) 14 14

Constellation mapping may also be defined as described below. N_(SD) ofthe 3×996-tone RU may be equal to 2940, when considering 48 pilots. And,N_(SD) of the 4×996-tone RU may be equal to 3920, when considering 64pilots. In the following equation, floor denotes a decreasing operation.

4.1.A. When DCM is not applied

d′ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , N_(SD)/3-1 for 3×996-tone RU    -   k=0, 1, . . . , N_(SD)/4-1 for 4×996-tone RU    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0, 1, 2 for 3×996-tone RU    -   1=0, 1, 2, 3 for 4×996-tone RU    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=D _(TM)(k mod(N _(SD)/3)/D _(TM))+floor(k*D _(TM)/(N _(SD)/3)) for3×996-tone RU

t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4)) for4×996-tone RU

4.1.B. When DCM is Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , 2N_(SD)/3-1 for 3×996-tone RU    -   k=0, 1, . . . , N_(SD)/2-1 for 4×996-tone RU    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0, 1, 2 for 3×996-tone RU    -   1=0, 1, 2, 3 for 4×996-tone RU    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1    -   For 3×996-tone RU

t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM)+floor(k*D) _(TM_DCM)/(N_(SD)/3)) for 0≤k<N _(SD)/3

t(k)=D _(TM_DCM)((K−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))+floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3 for N _(SD)/3≤k≤2N _(SD)/3-1

For 4×996-tone RU

t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4)) for 0<k<N _(SD)/4

t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))+floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4 for N _(SD)/4<k<N _(SD)/2-1

4.2. Newly Designed Situation

In 160 MHz, 2020/2018-tone RUs, and so on, may be newly defined, and thenumber of pilots being used may be equal to 16/32, and so on. N_(SD) ofa 2020-tone RU may be equal to 2004, when considering 16 pilots, andN_(SD) of the 2020-tone RU may be equal to 1988, when considering 32pilots. N_(SD) of a 2018-tone RU may be equal to 2002, when considering16 pilots, and N_(SD) of the 2018-tone RU may be equal to 1986, whenconsidering 32 pilots.

RU size (tones) 2020 2018 N_(SD) w/16 pilots 2004 2002 N_(SD) w/32pilots 1988 1986

In 240 MHz, 3044/3042-tone RUs, and so on, may be newly defined, and thenumber of pilots being used may be equal to 16/24/48, and so on. N_(SD)of a 3044-tone RU may be equal to 3028, when considering 16 pilots,N_(SD) of the 3044-tone RU may be equal to 3020, when considering 24pilots, and N_(SD) of the 3044-tone RU may be equal to 2996, whenconsidering 48 pilots. N_(SD) of a 3042-tone RU may be equal to 3026,when considering 16 pilots, N_(SD) of the 3042-tone RU may be equal to3018, when considering 24 pilots, and N_(SD) of the 3042-tone RU may beequal to 2994, when considering 48 pilots.

RU size (tones) 3044 3042 N_(SD) w/16 pilots 3028 3026 N_(SD) w/24pilots 3020 3018 N_(SD) w/48 pilots 2996 2994

In 320 MHz, 4068/4066-tone RUs, and so on, may be newly defined, and thenumber of pilots being used may be equal to 16/32/64, and so on. N_(SD)of a 4068-tone RU may be equal to 4052, when considering 16 pilots,N_(SD) of the 4068-tone RU may be equal to 4036, when considering 32pilots, and N_(SD) of the 4068-tone RU may be equal to 4004, whenconsidering 64 pilots. N_(SD) of a 4066-tone RU may be equal to 4050,when considering 16 pilots, N_(SD) of the 4066-tone RU may be equal to4034, when considering 32 pilots, and N_(SD) of the 4066-tone RU may beequal to 4002, when considering 64 pilots.

RU size (tones) 4068 4066 N_(SD) w/16 pilots 4052 4050 N_(SD) w/32pilots 4036 4034 N_(SD) w/64 pilots 4004 4002

Additionally, D_(TM) and D_(TM_DCM) per N_(SD) may each use one of thevalues listed below.

RU size (tones) 2020 2018 N_(SD) 2004 1988 2002 1986 (2{circumflex over( )}2*3*167) (2{circumflex over ( )}2*7*71) (2*7*11*13) (2*3*331) D_(TM)12/167 28/71 22/26 6/331 D_(TM) _(—) _(DCM) 12/167 14/28/71 11/13/146/331

RU size (tones) 3044 3042 N_(SD) 3028 3020 2996 3026 3018 2994(2{circumflex over ( )}2*757) (2{circumflex over ( )}2*5*151)(2{circumflex over ( )}2*7*107) (2*17*89) (2*3*503) (2*3*499) D_(TM) 75720/151 28 17/34 6/503 6/499 D_(TM) _(—) _(DCM) 757 10/20/151 14/28 17/346/503 6/499 RU size (tones) 4068 4066 N_(SD) 4052 4036 4004 4050 40344002 (2{circumflex over ( )}2*1013) (2*2*1009) (2{circumflex over( )}2*7*11*13) (2*3{circumflex over ( )}4*5{circumflex over ( )}2)(2*2017) (2*3*23*29) D_(TM) 4/1013 4/1009 22/26/28/44/5225/27/30/45/50/54 2/2017 23/29/46/58 D_(TM) _(—) _(DCM) 4/1013 4/100911/13/14/22/26/28 15/18/25/27/30/ 2/2017 6/23/29

Various tone mapping rules may be applied, as shown below, to thevarious RU and N_(SD) situations that are presented above.

4.2.A. Application of the Legacy Method

4.2.A.1) when DCM is not Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=D _(TM)(k mod N _(SD) /D _(TM))+floor(k*D _(TM) /N _(SD)))

4.2.A.2) when DCM is Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , 2N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=D _(TM_DCM)(k mod N _(SD) /D _(TM_DCM))+floor(k*D _(TM_DCM) /N_(SD)) for 0≤k<N _(SD)

t(k)=D _(TM_DCM)((k−N _(SD))mod N _(SD) /D _(TM_DCM))+floor((k−N_(SD))*D _(TM_DCM) /N _(SD))+N _(SD) for N _(SD) <k<2N _(SD)−1

4.2.B. New Method 1

A method of performing cyclic shift by half of the N_(SD) may beapplied.

4.2.B.1) when DCM is not Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , NSYM−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=(k+N_(SD)/2) mod N_(SD)

Additionally, the conventional (or legacy) method may be applied oncemore by substituting t(k) with k once again (performing once again theLDPC tone mapping by using a method of performing a cyclic shift by onehalf of N_(SD) after substituting (t(k) with k).

4.2.B.2) when DCM is Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , 2N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=(k+N _(SD)/2)mod N _(SD) for 0<k<N _(SD)

t(k)=(k−N _(SD) +N _(SD)/2)mod N _(SD) +N _(SD) for N _(SD) <k<2N_(SD)−1

Additionally, the conventional (or legacy) method may be applied oncemore by substituting t(k) with k once again (performing once again theLDPC tone mapping by using a method of performing a cyclic shift by onehalf of N_(SD) after substituting t(k) with k).

4.2.C. New Method 2

After performing tone mapping by using the conventional Equation 4.2.A,by substituting t(k) once again with k, a method of performing a cyclicshift by one half of N_(SD) (4.2.B) may be applied once more.

4.2.D. New Method 3

A method of first performing tone mapping by using the conventionalmethod and then reversing the process order and performing mapping maybe used, or a method of first reversing the process order and thenapplying the conventional method may be used (after mappingt(k)=(N_(SD)−1−k), the above-described LDPC tone mapping of 4.1 and 4.2is performed). The following shows a method of performing mapping byreversing the process order.

4.2.D.1) when DCM is not Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=(N _(SD)−1−k)

4.2.D.2) when DCM is Applied

d″ _(t(k),i,n,l,r,u) =d′ _(k,i,n,l,r,u)

-   -   where    -   k=0, 1, . . . , 2N_(SD)−1    -   i=1, . . . , N_(SS,r,u)    -   n=0, 1, . . . , N_(SYM)−1    -   1=0    -   u=0, . . . , N_(user,r)−1    -   r=0, . . . , N_(RU)−1

t(k)=(N _(SD)−1−k) for 0≤k<N _(SD)

t(k)=(2N _(SD)−1−k)+N _(SD) for N _(SD) ≤k≤2N _(SD)−1

The embodiments of 4.1 and 4.2 may correspond to the operationsdescribed in FIG. 23 to FIG. 28 . A complex constellation numberd′_(k,i,n,l,r,u) that is mapped to the data tones by the constellationmapper may obtain a complex constellation number d″_(t(k),i,n,l,r,u) viaLDPC tone mapping, which is similar to the interleaving operation. Then,the d′_(k,i,n,l,r,u) may be mapped in data tones that are spaced apartby D_(TM)−1. That is, as a result of the LDPC tone mapping operation,each of the two serially (or consecutively) generated complexconstellation numbers may be transmitted from two data tones each beingspaced apart by D_(TM)−1.

Additionally, if a band in which the data tones are transmitted is a2×996-tone RU or a larger RU, a frequency segment may be separated to1=0, 1, . . . , and so on, by the segment parser. The constellationmapping and LDPC tone mapping may be performed per frequency segment. IfDCM is applied, the data tones may be processed with LDPC tone mappingfor each of a lower half data subcarrier and an upper half datasubcarrier.

Since various LDPC tone mapping in a new RU have little difference inperformance, in order to reduce complexity, it may be preferable toapply the conventional method of 4.2.A. However, when the D_(TM) orD_(TM_DCM) is set to have a large value, in order to obtain frequencydiversity, the method of 4.2.C or 4.2.D may have more meaning.

FIG. 25 is a procedure flowchart showing operations of a transmittingdevice according to the present embodiment.

An example of FIG. 25 may be performed by a transmitting device (APand/or non-AP STA). Part of each step (or detailed sub-step that will bedescribed later on) in the example of FIG. 25 may be skipped (oromitted) or varied.

In step S2510, the transmitting device (or transmitting STA) may obtaininformation related to the above-described tone plan. As describedabove, the information related to the tone plan includes RU size,position, control information related to the RU, information related toa frequency band including the RU, information on the STA receiving theRU, and so on.

In step S2520, the transmitting STA may configure/generate a PPDU basedon the obtained control information. The step of configuring/generatinga PPDU may include a step of configuring/generating each field of thePPDU. That is, step S2520 includes a step of configuring anEHT-SIG-A/B/C field that includes control information related to a toneplan or sounding. That is, step 2520 may include a step of configuring afield that includes control information (e.g., N bitmap) indicating thesize/position of the RU and/or a field that includes an identifier(e.g., AID) of the STA receiving the RU.

Additionally, step S2520 may include a step of generating an STF/LTFsequence that is transmitted through a specific RU. The STF/LTF sequencemay be generated based on a preconfigured STA generating sequence/LTFgenerating sequence.

Additionally, step S2520 may include a step of generating a data field(i.e., MPDU) that is transmitted through a specific RU.

In step S2530, the transmitting device may transmit the PPDU, which isconfigured in step S2520, to a receiving device based on step S2530.

While performing step S2530, the transmitting device may perform atleast one of the operations of CSD, Spatial Mapping, IDFT/IFFToperation, GI insertion, and so on.

The signal(s)/field(s)/sequences(s) that is/are configured according tothe present specification may be transmitted in the format of FIG. 19 .

A method for configuring a data field of the PPDU through theabove-described step S2520 and step S2530 may be performed based on thedevice of FIG. 20 .

As shown in the drawing, the transmitting device may 1) perform PHYpadding, 2) perform a scrambling operation, and 3) perform LDPCencoding. Thereafter, the transmitting device may 4) perform a streamparsing operation that maps an LDPC-coded bit to a specific spatialstream, 5) perform a segment parsing operation that divides a frequencysegment when needed, 6) perform constellation mapping for an individualspatial stream and each frequency segment, and 7) perform LDPC tonemapping according to the present specification on a modulation symbolthat is generated based on constellation mapping.

Additionally, as shown in FIG. 1 , the transmitting device (ortransmitter) may include a memory 112, a processor 111, and atransceiver 113.

The memory 112 may store information on multiple Tone-Plans/RUs that aredescribed in the present specification.

The processor 111 may generate various RUs based on the informationstored in the memory 112 and may configure a PPDU. An example of thePPDU that is generated by the processor 111 may be the same as FIG. 1 .

The processor 111 may perform all/part of the operations shown in FIG.25 .

The transceiver 113 shown in the drawing include an antenna and mayperform analog signal processing. More specifically, the processor 111may control the transceiver 113 so that the PPDU generated by theprocessor 111 can be transmitted.

Alternatively, the processor 111 may generate a transmit PPDU and maystore information related to the transmit PPDU in the memory 112.

FIG. 26 is a procedure flowchart showing operations of a receivingdevice according to the present embodiment.

An example of FIG. 26 may be performed by a receiving device (AP and/ornon-AP STA).

An example of FIG. 26 may be performed by a receiving STA or receivingdevice (AP and/or non-AP STA). Part of each step (or detailed sub-stepthat will be described later on) in the example of FIG. 26 may beskipped (or omitted).

In step S2610, the receiving device (receiving STA) may receive all orpart of a PPDU. The received signal may have the format shown in FIG. 18.

A sub-step of step S2610 may be determined based on step S2530. That is,step S2610 may perform operations of recovering (or reconfiguring) theresults of the operations of CSD, Spatial Mapping, IDFT/IFFT operation,GI insertion, and so on, which are applied in step S2530.

In step S2620, the receiving device may perform decoding on all/part ofthe PPDU. Additionally, the receiving device may obtain controlinformation related to a Tone plan (i.e., RU) or sounding from thedecoded PPDU.

More specifically, the receiving device decodes an L-SIG and an EHT-SIGof the PPDU based on a Legacy STF/LTF and may obtain informationincluded in the L-SIG and EHT-SIG. Information on various tone plans(i.e., RUs) described in the present specification may be included inthe EHT-SIG (EHT-SIG-A/B/C, and so on), and the receiving STA may obtaininformation related to the tone plan (i.e., RU) through the EHT-SIG.

In step S2630, the receiving device may decode the remaining part of thePPDU based on the information related to the tone plan (i.e., RU) thatis obtained through step S2620. For example, the receiving STA maydecode an STF/LTF field of the PPDU based on the information related tothe tone plan (i.e., RU). Additionally, the receiving STA may decode adata field of the PPDU based on the information related to the tone plan(i.e., RU) and may obtain an MPDU that is included in the data field.

For example, the receiving device may perform a processing operation ofdelivering (or transferring) data that is decoded in step S2630 to ahigher layer (e.g., MAC layer). Furthermore, when signal generation isinstructed to the PHY layer from the higher layer in response to thedata that is delivered to the higher layer, subsequent operations may beperformed.

The above-described PPDU may be received based on the device of FIG. 1 .

As shown in FIG. 1 , a receiving device may include a memory 122, aprocessor 121, and a transceiver 123.

The transceiver 123 may receive a PPDU based on the control of theprocessor 121. For example, the transceiver 123 may include multipledetailed units (not shown). For example, the transceiver 123 may includeat least one receiving antenna and may include a filter for thecorresponding receiving antenna.

The PPDU that is received through the transceiver 123 may be stored inthe memory 122. The processor 121 may process decoding on the receivedPPDU through the memory 122. The processor 121 may obtain controlinformation related to the tone-plan/RU included in the PPDU and maystore the obtained control information in the memory 112.

The processor 121 may perform decoding on the received PPDU. Morespecifically, the processor 121 may perform operations of recovering (orreconfiguring) the results of the operations of CSD, Spatial Mapping,IDFT/IFFT operation, GI insertion, which are applied to the PPDU. Theoperations of recovering (or reconfiguring) the results of theoperations of CSD, Spatial Mapping, IDFT/IFFT operation, GI insertionmay be performed by multiple processing units (not shown) that areindividually implemented in the processor 121.

Additionally, the processor 121 may decode a data field of the receivedPPDU through the transceiver 123.

Also, the processor 121 may process the decoded data. For example, theprocessor 121 may perform a processing operation of delivering (ortransferring) information related to the decoded data field to a higherlayer (e.g., MAC layer). Furthermore, when signal generation isinstructed to the PHY layer from the higher layer in response to thedata that is delivered to the higher layer, subsequent operations may beperformed.

Hereinafter, the above-described embodiment will be described withreference to FIG. 1 to FIG. 26 .

FIG. 27 shows a flowchart showing a procedure of transmitting, by atransmitting STA, a PPDU in a wideband according to the presentembodiment.

The example of FIG. 27 may be performed in a network environment inwhich a next generation WLAN system (IEEE 802.11be or EHT WLAN system)is being supported. The next generation WLAN system is a WLAN systemthat is enhanced from an 802.11ax system and may, therefore, satisfybackward compatibility with the 802.11ax system.

The present embodiment proposes a method for performing LDPC tonemapping for a data bit sequence that is included in a data field of aPPDU, when the PPDU is transmitted at a wideband (240 MHz, 320 MHz band)that is supported by an EHT WLAN system. At this point, a tone plan ofthe wideband may be designed by repeating (or iterating) an 80 MHz toneplan of 802.11ax.

The example of FIG. 27 is performed by a transmitting STA, and thetransmitting STA may correspond to an access point (AP). A receiving STAof FIG. 27 may correspond to an STA that supports an Extremely HighThroughput (EHT) WLAN system.

In step S2710, a transmitting station (STA) generates a PhysicalProtocol Data Unit (PPDU).

In step S2720, the transmitting STA transmits the PPDU to a receivingSTA through a wideband.

The wideband may be a 240 MHz band or a 320 MHz band.

The PPDU may include a control field and a data field. The control fieldmay include a Universal-Signal (U-SIG) field and an EHT-SIG field.

Low Density Parity Check (LDPC) tone mapping is performed on data tonesincluded in the data field based on a first parameter. Morespecifically, the data field may be generated based on a bit stream. Thebit stream may be mapped to the data tones based on a constellationmapping. The data tones may be configured to have a tone spacing that isequivalent to the first parameter based on the LDPC tone mapping. TheLDPC tone mapping is similar to an interleaving operation, and the bitstream may be spread at a tone spacing of the first parameter based onthe LDPC tone mapping and may then be mapped to a data tone.Additionally, the bit stream may be modulated based on the constellationmapping before being processed with the LDPC tone mapping.

Furthermore, the bit stream may be divided per frequency segment by asegment parser before the constellation mapping is performed. Theconstellation mapping and the LDPC tone mapping may be performed perfrequency segment. A size of one frequency segment may be equal to a996-tone RU.

That is, 1) PHY padding may be performed, 2) a scrambling operation maybe performed, 3) LDPC encoding may be performed, 4) a stream parsingoperation that maps an LDPC-coded bit to a specific spatial stream maybe performed, 5) a segment parsing operation that divides a full band tofrequency segments (996-tone RU) may be performed, 6) the constellationmapping for an individual spatial stream and each frequency segment maybe performed, and 7) the LDPC tone mapping may be performed on amodulation symbol that is generated based on the constellation mapping.In the transmitting STA, the procedures from 1) to 7) are performed inthe listed order. And, the description of the present embodiment will befocused on the procedures from 5) to 7).

A tone plan of the 240 MHz band or the 320 MHz band is determined basedon the control field. That is, the control field included information ona tone plan, and the information on the tone plan may include a size andposition of an RU, control information related to the RU, informationrelated to the frequency band including the RU, information on an STAreceiving the RU, and so on.

Additionally, the control field may include information on a bandwidthof the wideband. The wideband may be determined as 240 MHz or 320 MHz(including both contiguous band and non-contiguous band) based on theinformation on the bandwidth of the wideband.

As an example of the tone plan, a tone plan of the 240 MHz band may be a3×996 tone Resource Unit (RU), a tone plan of the 320 MHz band may be a4×996 tone RU, and the first parameter may be equal to 20. The firstparameter may correspond to an LDPC tone mapping distance parameterD_(TM). The D_(TM) may be a tone spacing that is used in the LDPC tonemapping.

The 3×996-tone RU is a repetition of a 996-tone RU, which is an 80 MHztone plan of an 802.11ax WLAN system. Accordingly, when using a toneplan of a 3×996-tone RU in the 240 MHz band, D_(TM) that is used in the996-tone RU may be used as it is in the 3×996-tone RU (D_(TM)=20 in a996-tone RU). Additionally, the 4×996-tone RU is a repetition of a996-tone RU, which is an 80 MHz tone plan of an 802.11ax WLAN system.Accordingly, when using a tone plan of a 4×996-tone RU in the 320 MHzband, D_(TM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM)=20 in a 996-tone RU).

When the wideband is a 240 MHz band, the 3×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, and a third 996-tone RUby the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, and a third bit streamfor the third 996-tone RU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. That is, the constellation mapping is firstperformed per frequency segment, and, then, the LDPC tone mapping may beperformed afterwards.

The first to third data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to third data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to third data tones may be determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/3)/D _(TM))+floor(k*D _(TM)/(N _(SD)/3))

Herein, t(k) is an index of the first to third data tones, D_(TM) is thefirst parameter, k is an index of a tone having the first to third bitstreams mapped thereto, N_(SD) is a number of the data tones, and flooris a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto third bit streams, the first bit stream may be mapped to a fourthdata tone based on a first constellation mapping and mapped to a fifthdata tone based on a second constellation mapping. The second bit streammay be mapped to a sixth data tone based on a third constellationmapping and mapped to a seventh data tone based on a fourthconstellation mapping. The third bit stream may be mapped to an eighthdata tone based on a fifth constellation mapping and mapped to a ninthdata tone based on a sixth constellation mapping.

The first to sixth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fourth to ninth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fourth to ninth data tones may be included in the data tones. Atthis point, the second parameter may be equal to 14.

The second parameter may correspond to an LDPC tone mapping distanceparameter D_(TM_DCM) in a case where the DCM scheme is applied. TheD_(TM_DCM) may be a tone spacing that is used in the LDPC tone mappingin the case where the DCM scheme is applied. Similarly, in the3×996-tone RU, D_(TM_DCM) that is used in the 996-tone RU may be used asit is (D_(TM_DCM)=14 in a 996-tone RU). And, in the 4×996-tone RU,D_(TM_DCM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM_DCM)=14 in a 996-tone RU).

When the DCM is being applied, the fourth, sixth and eighth data tonesmay be lower half tones (or subcarrier k) within a frequency, and thefifth, seven and ninth data tones may be upper half tones (or subcarrierk+N/2) within the frequency. Herein, a tone and a subcarrier may beinterchangeably used.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fourth toninth data tones being spread as much as the second parameter may be asdescribed below.

Indexes of the fourth, sixth, and eighth data tones may be determined asfollows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/3))

Herein, t(k) is an index of the fourth, sixth, and eighth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

Indexes of the fifth, seventh, and ninth data tones may be determined asfollows.

t(k)=D _(TM_DCM)((k−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))+floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3

Herein, t(k) is an index of the fifth, seventh, and ninth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). Thefirst modulation symbol may be mapped to the fourth data tone, and thesecond modulation symbol may be mapped to the fifth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). And, the fourth modulationsymbol may be mapped to the sixth data tone, and the fifth modulationsymbol may be mapped to the seventh data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth mapping constellation andmodulated to a sixth modulation symbol based on the sixth constellationmapping. A bit order of a first bit group for the sixth modulationsymbol may be different from a bit order of a second bit group for thefifth modulation symbol ((B_(4k), B_(4k+1), B_(4k+2),B_(4k+3))−>(B_(4k+1), B_(4k), B_(4k+3), B_(4k+2))) The first and secondbit groups may be included in the third bit stream. And, the fifthmodulation symbol may be mapped to the eighth data tone, and the sixthmodulation symbol may be mapped to the ninth data tone.

When the wideband is a 320 MHz band, the 4×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, a third 996-tone RU, anda fourth 996-tone RU by the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, a third bit stream forthe third 996-tone RU, and a fourth bit stream for the fourth 996-toneRU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. The fourth bit stream may be mapped to afourth data tone based on the constellation mapping, and the fourth datatone may be set to have tone spacing that is equivalent to the firstparameter based on the LDPC tone mapping. That is, the constellationmapping is first performed per frequency segment, and, then, the LDPCtone mapping may be performed afterwards.

The first to fourth data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to fourth data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to fourth data tones are determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4))

Herein, t(k) may be an index of the first to fourth data tones, D_(TM)may be the first parameter, k may be an index of a tone having the firstto fourth bit streams mapped thereto, N_(SD) may be a number of the datatones, and floor may be a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto fourth bit streams, the first bit stream may be mapped to a fifthdata tone based on a first constellation mapping and mapped to a sixthdata tone based on the second constellation mapping. The second bitstream may be mapped to a seventh data tone based on a thirdconstellation mapping and mapped to an eighth data tone based on thefourth constellation mapping. The third bit stream may be mapped to aninth data tone based on a fifth constellation mapping and mapped to atenth data tone based on the sixth constellation mapping. The fourth bitstream may be mapped to an eleventh data tone based on a seventhconstellation mapping and mapped to a twelfth data tone based on theeighth constellation mapping.

The first to eighth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fifth to twelfth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fifth to twelfth data tones may be included in the data tones. Thesecond parameter may be equal to 14. Details on the second parameter aredescribed above.

When the DCM is being applied, the fifth, seventh, ninth and eleventhdata tones may be lower half tones within a frequency. And, the sixth,eighth, tenth and twelfth data tones may be upper half tones within thefrequency.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fifth totwelfth data tones being spread as much as the second parameter may beas described below.

Indexes of the fifth, seventh, ninth and eleventh data tones may bedetermined as follows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4))

Herein, t(k) may be an index of the fifth, seventh, ninth and eleventhdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

Indexes of the sixth, eighth, tenth and twelfth data tones aredetermined as follows.

t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))+floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4

Herein, t(k) may be an index of the sixth, eighth, tenth and twelfthdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). And,the first modulation symbol may be mapped to the fifth data tone, andthe second modulation symbol may be mapped to the sixth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). The fourth modulation symbolmay be mapped to the seventh data tone, and the fifth modulation symbolmay be mapped to the eighth data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth constellation mapping and asixth modulation symbol based on the sixth constellation mapping. A bitorder of a first bit group for the sixth modulation symbol may bedifferent from a bit order of a second bit group for the fifthmodulation symbol ((B_(4k), B_(4k+1), B_(4k+2), B_(4k+3))−>(B_(4k+1),B_(4k), B_(4k+3), B_(4k+2))). The first and second bit groups may beincluded in the third bit stream. The fifth modulation symbol may bemapped to the ninth data tone, and the sixth modulation symbol may bemapped to the tenth data tone.

For example, if the seventh and eighth constellation mappings are theBPSK modulation scheme, the fourth bit stream may be modulated to aseventh modulation symbol based on the seventh constellation mapping andmodulated to an eighth modulation symbol based on the eighthconstellation mapping. The eighth modulation symbol may be generated byapplying phase rotation to the seventh modulation symbol(d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). The seventh modulation symbol may bemapped to the eleventh data tone, and the eighth modulation symbol maybe mapped to the twelfth data tone.

The 3×996-tone RU may include 48 pilot tones and 2940 data tones. And,the 4×996-tone RU may include 64 pilot tones and 3920 data tones.

Furthermore, the PPDU may further include a Legacy-Signal (L-SIG) field,a Repeated Legacy-Signal (RL-SIG) field, an EHT-Short Training Field(STF), an EHT-Long Training Field (LTF). The EHT-SIG field may includean EHT-SIG-A field and an EHT-SIG-B field. The EHT-SIG field may furtherinclude an EHT-SIG-C field.

FIG. 28 shows a flowchart showing a procedure of receiving, by areceiving STA, a PPDU in a wideband according to the present embodiment.

The example of FIG. 28 may be performed in a network environment inwhich a next generation WLAN system (IEEE 802.11be or EHT WLAN system)is being supported. The next generation WLAN system is a WLAN systemthat is enhanced from an 802.11ax system and may, therefore, satisfybackward compatibility with the 802.11ax system.

The present embodiment proposes a method for performing LDPC tonemapping for a data bit sequence that is included in a data field of aPPDU, when the PPDU is transmitted at a wideband (240 MHz, 320 MHz band)that is supported by an EHT WLAN system. At this point, a tone plan ofthe wideband may be designed by repeating (or iterating) an 80 MHz toneplan of 802.11ax.

The example of FIG. 28 may be performed by a receiving station (STA),and the receiving STA may correspond to an STA that supports anExtremely High Throughput (EHT) WLAN system. A transmitting STA of FIG.28 may correspond to an access point (AP).

In step S2810, a receiving STA receives a Physical Protocol Data Unit(PPDU) from a transmitting STA through a wideband.

In step S2820, the receiving STA decodes the PPDU.

The wideband may be a 240 MHz band or a 320 MHz band.

The PPDU may include a control field and a data field. The control fieldmay include a Universal-Signal (U-SIG) field and an EHT-SIG field.

Low Density Parity Check (LDPC) tone mapping is performed on data tonesincluded in the data field based on a first parameter. Morespecifically, the data field may be generated based on a bit stream. Thebit stream may be mapped to the data tones based on a constellationmapping. The data tones may be configured to have a tone spacing that isequivalent to the first parameter based on the LDPC tone mapping. TheLDPC tone mapping is similar to an interleaving operation, and the bitstream may be spread at a tone spacing of the first parameter based onthe LDPC tone mapping and may then be mapped to a data tone.Additionally, the bit stream may be modulated based on the constellationmapping before being processed with the LDPC tone mapping.

Furthermore, the bit stream may be divided per frequency segment by asegment parser before the constellation mapping is performed. Theconstellation mapping and the LDPC tone mapping may be performed perfrequency segment. A size of one frequency segment may be equal to a996-tone RU.

That is, 1) PHY padding may be performed, 2) a scrambling operation maybe performed, 3) LDPC encoding may be performed, 4) a stream parsingoperation that maps an LDPC-coded bit to a specific spatial stream maybe performed, 5) a segment parsing operation that divides a full band tofrequency segments (996-tone RU) may be performed, 6) the constellationmapping for an individual spatial stream and each frequency segment maybe performed, and 7) the LDPC tone mapping may be performed on amodulation symbol that is generated based on the constellation mapping.In the transmitting STA, the procedures from 1) to 7) are performed inthe listed order. And, the description of the present embodiment will befocused on the procedures from 5) to 7).

However, since the receiving STA performs decoding of the data field,the procedures from 1) to 7) may be performed in a reversed order. AnSTA having received the data field of the transmitting device may 8)perform LDPC tone demapping, 9) perform constellation demapping so as toonce again obtain a bit sequence from a modulation symbol, 10) notperform mapping on the bit sequence per spatial stream or frequencysegment through a stream deparser or segment deparser, 11) perform LDPCdecoding, 12) perform a descrambling operation, and 13) perform Pre-FECpadding or Post-FEC padding. The receiving STA may decode the bit stream(input bit stream) through the procedures from 8) to 13).

A tone plan of the 240 MHz band or the 320 MHz band is determined basedon the control field. That is, the control field included information ona tone plan, and the information on the tone plan may include a size andposition of an RU, control information related to the RU, informationrelated to the frequency band including the RU, information on an STAreceiving the RU, and so on.

Additionally, the control field may include information on a bandwidthof the wideband. The wideband may be determined as 240 MHz or 320 MHz(including both contiguous band and non-contiguous band) based on theinformation on the bandwidth of the wideband.

As an example of the tone plan, a tone plan of the 240 MHz band may be a3×996 tone Resource Unit (RU), a tone plan of the 320 MHz band may be a4×996 tone RU, and the first parameter may be equal to 20. The firstparameter may correspond to an LDPC tone mapping distance parameterD_(TM). The D_(TM) may be a tone spacing that is used in the LDPC tonemapping.

The 3×996-tone RU is a repetition of a 996-tone RU, which is an 80 MHztone plan of an 802.11ax WLAN system. Accordingly, when using a toneplan of a 3×996-tone RU in the 240 MHz band, D_(TM) that is used in the996-tone RU may be used as it is in the 3×996-tone RU (D_(TM)=20 in a996-tone RU). Additionally, the 4×996-tone RU is a repetition of a996-tone RU, which is an 80 MHz tone plan of an 802.11ax WLAN system.Accordingly, when using a tone plan of a 4×996-tone RU in the 320 MHzband, D_(TM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM)=20 in a 996-tone RU).

When the wideband is a 240 MHz band, the 3×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, and a third 996-tone RUby the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, and a third bit streamfor the third 996-tone RU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. That is, the constellation mapping is firstperformed per frequency segment, and, then, the LDPC tone mapping may beperformed afterwards.

The first to third data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to third data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to third data tones may be determined as follows.

t(k)=D _(TM)(k mod (N _(SD)/3)/D _(TM))+floor(k*D _(TM)/(N _(SD)/3))

Herein, t(k) is an index of the first to third data tones, D_(TM) is thefirst parameter, k is an index of a tone having the first to third bitstreams mapped thereto, N_(SD) is a number of the data tones, and flooris a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto third bit streams, the first bit stream may be mapped to a fourthdata tone based on a first constellation mapping and mapped to a fifthdata tone based on a second constellation mapping. The second bit streammay be mapped to a sixth data tone based on a third constellationmapping and mapped to a seventh data tone based on a fourthconstellation mapping. The third bit stream may be mapped to an eighthdata tone based on a fifth constellation mapping and mapped to a ninthdata tone based on a sixth constellation mapping.

The first to sixth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fourth to ninth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fourth to ninth data tones may be included in the data tones. Atthis point, the second parameter may be equal to 14.

The second parameter may correspond to an LDPC tone mapping distanceparameter D_(TM_DCM) in a case where the DCM scheme is applied. TheD_(TM_DCM) may be a tone spacing that is used in the LDPC tone mappingin the case where the DCM scheme is applied. Similarly, in the3×996-tone RU, D_(TM_DCM) that is used in the 996-tone RU may be used asit is (D_(TM_DCM)=14 in a 996-tone RU). And, in the 4×996-tone RU,D_(TM_DCM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM_DCM)=14 in a 996-tone RU).

When the DCM is being applied, the fourth, sixth and eighth data tonesmay be lower half tones (or subcarrier k) within a frequency, and thefifth, seven and ninth data tones may be upper half tones (or subcarrierk+N/2) within the frequency. Herein, a tone and a subcarrier may beinterchangeably used.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fourth toninth data tones being spread as much as the second parameter may be asdescribed below.

Indexes of the fourth, sixth, and eighth data tones may be determined asfollows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/3))

Herein, t(k) is an index of the fourth, sixth, and eighth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

Indexes of the fifth, seventh, and ninth data tones may be determined asfollows.

t(k)=D _(TM_DCM)((k−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))+floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3

Herein, t(k) is an index of the fifth, seventh, and ninth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). Thefirst modulation symbol may be mapped to the fourth data tone, and thesecond modulation symbol may be mapped to the fifth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). And, the fourth modulationsymbol may be mapped to the sixth data tone, and the fifth modulationsymbol may be mapped to the seventh data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth mapping constellation andmodulated to a sixth modulation symbol based on the sixth constellationmapping. A bit order of a first bit group for the sixth modulationsymbol may be different from a bit order of a second bit group for thefifth modulation symbol ((B_(4k), B_(4k+1), B_(4k+2),B_(4k+3))−>(B_(4k+1), B_(4k), B_(4k+3), B_(4k+2))) The first and secondbit groups may be included in the third bit stream. And, the fifthmodulation symbol may be mapped to the eighth data tone, and the sixthmodulation symbol may be mapped to the ninth data tone.

When the wideband is a 320 MHz band, the 4×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, a third 996-tone RU, anda fourth 996-tone RU by the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, a third bit stream forthe third 996-tone RU, and a fourth bit stream for the fourth 996-toneRU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. The fourth bit stream may be mapped to afourth data tone based on the constellation mapping, and the fourth datatone may be set to have tone spacing that is equivalent to the firstparameter based on the LDPC tone mapping. That is, the constellationmapping is first performed per frequency segment, and, then, the LDPCtone mapping may be performed afterwards.

The first to fourth data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to fourth data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to fourth data tones are determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4))

Herein, t(k) may be an index of the first to fourth data tones, D_(TM)may be the first parameter, k may be an index of a tone having the firstto fourth bit streams mapped thereto, N_(SD) may be a number of the datatones, and floor may be a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto fourth bit streams, the first bit stream may be mapped to a fifthdata tone based on a first constellation mapping and mapped to a sixthdata tone based on the second constellation mapping. The second bitstream may be mapped to a seventh data tone based on a thirdconstellation mapping and mapped to an eighth data tone based on thefourth constellation mapping. The third bit stream may be mapped to aninth data tone based on a fifth constellation mapping and mapped to atenth data tone based on the sixth constellation mapping. The fourth bitstream may be mapped to an eleventh data tone based on a seventhconstellation mapping and mapped to a twelfth data tone based on theeighth constellation mapping.

The first to eighth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fifth to twelfth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fifth to twelfth data tones may be included in the data tones. Thesecond parameter may be equal to 14. Details on the second parameter aredescribed above.

When the DCM is being applied, the fifth, seventh, ninth and eleventhdata tones may be lower half tones within a frequency. And, the sixth,eighth, tenth and twelfth data tones may be upper half tones within thefrequency.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fifth totwelfth data tones being spread as much as the second parameter may beas described below.

Indexes of the fifth, seventh, ninth and eleventh data tones may bedetermined as follows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4))

Herein, t(k) may be an index of the fifth, seventh, ninth and eleventhdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

Indexes of the sixth, eighth, tenth and twelfth data tones aredetermined as follows.

t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))+floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4

Herein, t(k) may be an index of the sixth, eighth, tenth and twelfthdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). And,the first modulation symbol may be mapped to the fifth data tone, andthe second modulation symbol may be mapped to the sixth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). The fourth modulation symbolmay be mapped to the seventh data tone, and the fifth modulation symbolmay be mapped to the eighth data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth constellation mapping and asixth modulation symbol based on the sixth constellation mapping. A bitorder of a first bit group for the sixth modulation symbol may bedifferent from a bit order of a second bit group for the fifthmodulation symbol ((B_(4k), B_(4k+1), B_(4k+2), B_(4k+3))−>(B_(4k+1),B_(4k), B_(4k+3), B_(4k+2))). The first and second bit groups may beincluded in the third bit stream. The fifth modulation symbol may bemapped to the ninth data tone, and the sixth modulation symbol may bemapped to the tenth data tone.

For example, if the seventh and eighth constellation mappings are theBPSK modulation scheme, the fourth bit stream may be modulated to aseventh modulation symbol based on the seventh constellation mapping andmodulated to an eighth modulation symbol based on the eighthconstellation mapping. The eighth modulation symbol may be generated byapplying phase rotation to the seventh modulation symbol(d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). The seventh modulation symbol may bemapped to the eleventh data tone, and the eighth modulation symbol maybe mapped to the twelfth data tone.

The 3×996-tone RU may include 48 pilot tones and 2940 data tones. And,the 4×996-tone RU may include 64 pilot tones and 3920 data tones.

Furthermore, the PPDU may further include a Legacy-Signal (L-SIG) field,a Repeated Legacy-Signal (RL-SIG) field, an EHT-Short Training Field(STF), an EHT-Long Training Field (LTF). The EHT-SIG field may includean EHT-SIG-A field and an EHT-SIG-B field. The EHT-SIG field may furtherinclude an EHT-SIG-C field.

4. Device Configuration

FIG. 29 illustrates an example of a modified transmitting device and/orreceiving device of the present specification.

Each device/STA shown in sub-figures (a)/(b) of FIG. 1 may be modifiedas shown in FIG. 29 . A transceiver 630 of FIG. 29 may be the same asthe transceiver(s) 113 and 123 of FIG. 1 . The transceiver 630 of FIG.29 may include a receiver and a transmitter.

A processor 610 of FIG. 29 may be the same as the processor(s) 111 and121 shown in FIG. 1 . Alternatively, the processor 610 of FIG. 29 may bethe same as the processing chip(s) 114 and 124 shown in FIG. 1 .

A memory 150 of FIG. 29 may be the same as the memory(s) 112 and 122shown in FIG. 1 . Alternatively, the memory 150 of FIG. 29 may be aseparate external memory that is different from the memory(s) 112 and122 shown in FIG. 1 .

Referring to FIG. 29 , the power management module 611 manages power forthe processor 610 and/or the transceiver 630. The battery 612 suppliespower to the power management module 611. The display 613 outputsresults processed by the processor 610. The keypad 614 receives inputsthat are to be used by the processor 610. The keypad 614 may be shown onthe display 613. The SIM card 615 may be an integrated circuit that isintended to securely store the international mobile subscriber identity(IMSI) number and its related key, which are used to identify andauthenticate subscribers on mobile telephony devices, such as mobilephones and computers.

Referring to FIG. 29 , the speaker 640 may output sound-related resultsprocessed by the processor 610. The microphone 641 may receivesound-related inputs to be used by the processor 610.

The above-described technical features of the present specification maybe applied to various devices and methods. For example, theabove-described technical features of the present specification may beperformed/supported through the device(s) of FIG. 1 and/or FIG. 29 . Forexample, the above-described technical features of the presentspecification may be applied to only part of FIG. 1 and/or FIG. 29 . Forexample, the above-described technical features of the presentspecification may be implemented based on the processing chip(s) 114 and124 of FIG. 1 , or implemented based on the processor(s) 111 and 121 andthe memory(s) 112 and 122, or implemented based on the processor 610 andthe memory 620 of FIG. 29 . For example, the device according to thepresent specification receives a Physical Protocol Data Unit (PPDU) froma transmitting station (STA) through a wideband, and decodes the PPDU.

The wideband may be a 240 MHz band or a 320 MHz band.

The PPDU may include a control field and a data field. The control fieldmay include a Universal-Signal (U-SIG) field and an EHT-SIG field.

Low Density Parity Check (LDPC) tone mapping is performed on data tonesincluded in the data field based on a first parameter. Morespecifically, the data field may be generated based on a bit stream. Thebit stream may be mapped to the data tones based on a constellationmapping. The data tones may be configured to have a tone spacing that isequivalent to the first parameter based on the LDPC tone mapping. TheLDPC tone mapping is similar to an interleaving operation, and the bitstream may be spread at a tone spacing of the first parameter based onthe LDPC tone mapping and may then be mapped to a data tone.Additionally, the bit stream may be modulated based on the constellationmapping before being processed with the LDPC tone mapping.

Furthermore, the bit stream may be divided per frequency segment by asegment parser before the constellation mapping is performed. Theconstellation mapping and the LDPC tone mapping may be performed perfrequency segment. A size of one frequency segment may be equal to a996-tone RU.

That is, 1) PHY padding may be performed, 2) a scrambling operation maybe performed, 3) LDPC encoding may be performed, 4) a stream parsingoperation that maps an LDPC-coded bit to a specific spatial stream maybe performed, 5) a segment parsing operation that divides a full band tofrequency segments (996-tone RU) may be performed, 6) the constellationmapping for an individual spatial stream and each frequency segment maybe performed, and 7) the LDPC tone mapping may be performed on amodulation symbol that is generated based on the constellation mapping.In the transmitting STA, the procedures from 1) to 7) are performed inthe listed order. And, the description of the present embodiment will befocused on the procedures from 5) to 7).

A tone plan of the 240 MHz band or the 320 MHz band is determined basedon the control field. That is, the control field included information ona tone plan, and the information on the tone plan may include a size andposition of an RU, control information related to the RU, informationrelated to the frequency band including the RU, information on an STAreceiving the RU, and so on.

Additionally, the control field may include information on a bandwidthof the wideband. The wideband may be determined as 240 MHz or 320 MHz(including both contiguous band and non-contiguous band) based on theinformation on the bandwidth of the wideband.

As an example of the tone plan, a tone plan of the 240 MHz band may be a3×996 tone Resource Unit (RU), a tone plan of the 320 MHz band may be a4×996 tone RU, and the first parameter may be equal to 20. The firstparameter may correspond to an LDPC tone mapping distance parameterD_(TM). The D_(TM) may be a tone spacing that is used in the LDPC tonemapping.

The 3×996-tone RU is a repetition of a 996-tone RU, which is an 80 MHztone plan of an 802.11ax WLAN system. Accordingly, when using a toneplan of a 3×996-tone RU in the 240 MHz band, D_(TM) that is used in the996-tone RU may be used as it is in the 3×996-tone RU (D_(TM)=20 in a996-tone RU). Additionally, the 4×996-tone RU is a repetition of a996-tone RU, which is an 80 MHz tone plan of an 802.11ax WLAN system.Accordingly, when using a tone plan of a 4×996-tone RU in the 320 MHzband, D_(TM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM)=20 in a 996-tone RU).

When the wideband is a 240 MHz band, the 3×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, and a third 996-tone RUby the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, and a third bit streamfor the third 996-tone RU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. That is, the constellation mapping is firstperformed per frequency segment, and, then, the LDPC tone mapping may beperformed afterwards.

The first to third data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to third data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to third data tones may be determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/3)/D _(TM))+floor(k*D _(TM)(N _(SD)/3))

Herein, t(k) is an index of the first to third data tones, D_(TM) is thefirst parameter, k is an index of a tone having the first to third bitstreams mapped thereto, N_(SD) is a number of the data tones, and flooris a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto third bit streams, the first bit stream may be mapped to a fourthdata tone based on a first constellation mapping and mapped to a fifthdata tone based on a second constellation mapping. The second bit streammay be mapped to a sixth data tone based on a third constellationmapping and mapped to a seventh data tone based on a fourthconstellation mapping. The third bit stream may be mapped to an eighthdata tone based on a fifth constellation mapping and mapped to a ninthdata tone based on a sixth constellation mapping.

The first to sixth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fourth to ninth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fourth to ninth data tones may be included in the data tones. Atthis point, the second parameter may be equal to 14.

The second parameter may correspond to an LDPC tone mapping distanceparameter D_(TM_DCM) in a case where the DCM scheme is applied. TheD_(TM_DCM) may be a tone spacing that is used in the LDPC tone mappingin the case where the DCM scheme is applied. Similarly, in the3×996-tone RU, D_(TM_DCM) that is used in the 996-tone RU may be used asit is (D_(TM_DCM)=14 in a 996-tone RU). And, in the 4×996-tone RU,D_(TM_DCM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM_DCM)=14 in a 996-tone RU).

When the DCM is being applied, the fourth, sixth and eighth data tonesmay be lower half tones (or subcarrier k) within a frequency, and thefifth, seven and ninth data tones may be upper half tones (or subcarrierk+N/2) within the frequency. Herein, a tone and a subcarrier may beinterchangeably used.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fourth toninth data tones being spread as much as the second parameter may be asdescribed below.

Indexes of the fourth, sixth, and eighth data tones may be determined asfollows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/3))

Herein, t(k) is an index of the fourth, sixth, and eighth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

Indexes of the fifth, seventh, and ninth data tones may be determined asfollows.

t(k)=D _(TM_DCM)((k−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))+floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3

Herein, t(k) is an index of the fifth, seventh, and ninth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). Thefirst modulation symbol may be mapped to the fourth data tone, and thesecond modulation symbol may be mapped to the fifth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). And, the fourth modulationsymbol may be mapped to the sixth data tone, and the fifth modulationsymbol may be mapped to the seventh data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth mapping constellation andmodulated to a sixth modulation symbol based on the sixth constellationmapping. A bit order of a first bit group for the sixth modulationsymbol may be different from a bit order of a second bit group for thefifth modulation symbol ((B_(4k), B_(4k+1), B_(4k+2),B_(4k+3))−>(B_(4k+1), B_(4k), B_(4k+3), B_(4k+2))) The first and secondbit groups may be included in the third bit stream. And, the fifthmodulation symbol may be mapped to the eighth data tone, and the sixthmodulation symbol may be mapped to the ninth data tone.

When the wideband is a 320 MHz band, the 4×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, a third 996-tone RU, anda fourth 996-tone RU by the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, a third bit stream forthe third 996-tone RU, and a fourth bit stream for the fourth 996-toneRU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. The fourth bit stream may be mapped to afourth data tone based on the constellation mapping, and the fourth datatone may be set to have tone spacing that is equivalent to the firstparameter based on the LDPC tone mapping. That is, the constellationmapping is first performed per frequency segment, and, then, the LDPCtone mapping may be performed afterwards.

The first to fourth data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to fourth data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to fourth data tones are determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4))

Herein, t(k) may be an index of the first to fourth data tones, D_(TM)may be the first parameter, k may be an index of a tone having the firstto fourth bit streams mapped thereto, N_(SD) may be a number of the datatones, and floor may be a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto fourth bit streams, the first bit stream may be mapped to a fifthdata tone based on a first constellation mapping and mapped to a sixthdata tone based on the second constellation mapping. The second bitstream may be mapped to a seventh data tone based on a thirdconstellation mapping and mapped to an eighth data tone based on thefourth constellation mapping. The third bit stream may be mapped to aninth data tone based on a fifth constellation mapping and mapped to atenth data tone based on the sixth constellation mapping. The fourth bitstream may be mapped to an eleventh data tone based on a seventhconstellation mapping and mapped to a twelfth data tone based on theeighth constellation mapping.

The first to eighth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fifth to twelfth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fifth to twelfth data tones may be included in the data tones. Thesecond parameter may be equal to 14. Details on the second parameter aredescribed above.

When the DCM is being applied, the fifth, seventh, ninth and eleventhdata tones may be lower half tones within a frequency. And, the sixth,eighth, tenth and twelfth data tones may be upper half tones within thefrequency.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fifth totwelfth data tones being spread as much as the second parameter may beas described below.

Indexes of the fifth, seventh, ninth and eleventh data tones may bedetermined as follows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4))

Herein, t(k) may be an index of the fifth, seventh, ninth and eleventhdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

Indexes of the sixth, eighth, tenth and twelfth data tones aredetermined as follows.

t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))+floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4

Herein, t(k) may be an index of the sixth, eighth, tenth and twelfthdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). And,the first modulation symbol may be mapped to the fifth data tone, andthe second modulation symbol may be mapped to the sixth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). The fourth modulation symbolmay be mapped to the seventh data tone, and the fifth modulation symbolmay be mapped to the eighth data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth constellation mapping and asixth modulation symbol based on the sixth constellation mapping. A bitorder of a first bit group for the sixth modulation symbol may bedifferent from a bit order of a second bit group for the fifthmodulation symbol ((B_(4k), B_(4k+1), B_(4k+2), B_(4k+3))−>(B_(4k+1),B_(4k), B_(4k+3), B_(4k+2))). The first and second bit groups may beincluded in the third bit stream. The fifth modulation symbol may bemapped to the ninth data tone, and the sixth modulation symbol may bemapped to the tenth data tone.

For example, if the seventh and eighth constellation mappings are theBPSK modulation scheme, the fourth bit stream may be modulated to aseventh modulation symbol based on the seventh constellation mapping andmodulated to an eighth modulation symbol based on the eighthconstellation mapping. The eighth modulation symbol may be generated byapplying phase rotation to the seventh modulation symbol(d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). The seventh modulation symbol may bemapped to the eleventh data tone, and the eighth modulation symbol maybe mapped to the twelfth data tone.

The 3×996-tone RU may include 48 pilot tones and 2940 data tones. And,the 4×996-tone RU may include 64 pilot tones and 3920 data tones.

Furthermore, the PPDU may further include a Legacy-Signal (L-SIG) field,a Repeated Legacy-Signal (RL-SIG) field, an EHT-Short Training Field(STF), an EHT-Long Training Field (LTF). The EHT-SIG field may includean EHT-SIG-A field and an EHT-SIG-B field. The EHT-SIG field may furtherinclude an EHT-SIG-C field.

The technical features of the present specification may be implementedbased on a computer readable medium (CRM). For example, the CRM that isproposed in the present specification is a computer readable mediumincluding an instruction being executed by at least one processor.

The CRM may store instructions performing operations including the stepsof receiving a Physical Protocol Data Unit (PPDU) from a transmittingstation (STA), and decoding the PPDU. The instructions that are storedin the CRM of the present specification may be executed by at least oneprocessor. At least one processor being related to the CRM of thepresent specification may be the processor(s) 111 and 121 or processingchip(s) 114 and 124 of FIG. 1 , or the processor 610 of FIG. 29 .Meanwhile, the CRM of the present specification may be the memory(s) 112and 122 of FIG. 1 , or the memory 620 of FIG. 29 , or a separateexternal memory/storage medium/disc, and so on.

The wideband may be a 240 MHz band or a 320 MHz band.

The PPDU may include a control field and a data field. The control fieldmay include a Universal-Signal (U-SIG) field and an EHT-SIG field.

Low Density Parity Check (LDPC) tone mapping is performed on data tonesincluded in the data field based on a first parameter. Morespecifically, the data field may be generated based on a bit stream. Thebit stream may be mapped to the data tones based on a constellationmapping. The data tones may be configured to have a tone spacing that isequivalent to the first parameter based on the LDPC tone mapping. TheLDPC tone mapping is similar to an interleaving operation, and the bitstream may be spread at a tone spacing of the first parameter based onthe LDPC tone mapping and may then be mapped to a data tone.Additionally, the bit stream may be modulated based on the constellationmapping before being processed with the LDPC tone mapping.

Furthermore, the bit stream may be divided per frequency segment by asegment parser before the constellation mapping is performed. Theconstellation mapping and the LDPC tone mapping may be performed perfrequency segment. A size of one frequency segment may be equal to a996-tone RU.

That is, 1) PHY padding may be performed, 2) a scrambling operation maybe performed, 3) LDPC encoding may be performed, 4) a stream parsingoperation that maps an LDPC-coded bit to a specific spatial stream maybe performed, 5) a segment parsing operation that divides a full band tofrequency segments (996-tone RU) may be performed, 6) the constellationmapping for an individual spatial stream and each frequency segment maybe performed, and 7) the LDPC tone mapping may be performed on amodulation symbol that is generated based on the constellation mapping.In the transmitting STA, the procedures from 1) to 7) are performed inthe listed order. And, the description of the present embodiment will befocused on the procedures from 5) to 7).

A tone plan of the 240 MHz band or the 320 MHz band is determined basedon the control field. That is, the control field included information ona tone plan, and the information on the tone plan may include a size andposition of an RU, control information related to the RU, informationrelated to the frequency band including the RU, information on an STAreceiving the RU, and so on.

Additionally, the control field may include information on a bandwidthof the wideband. The wideband may be determined as 240 MHz or 320 MHz(including both contiguous band and non-contiguous band) based on theinformation on the bandwidth of the wideband.

As an example of the tone plan, a tone plan of the 240 MHz band may be a3×996 tone Resource Unit (RU), a tone plan of the 320 MHz band may be a4×996 tone RU, and the first parameter may be equal to 20. The firstparameter may correspond to an LDPC tone mapping distance parameterD_(TM). The D_(TM) may be a tone spacing that is used in the LDPC tonemapping.

The 3×996-tone RU is a repetition of a 996-tone RU, which is an 80 MHztone plan of an 802.11ax WLAN system. Accordingly, when using a toneplan of a 3×996-tone RU in the 240 MHz band, D_(TM) that is used in the996-tone RU may be used as it is in the 3×996-tone RU (D_(TM)=20 in a996-tone RU). Additionally, the 4×996-tone RU is a repetition of a996-tone RU, which is an 80 MHz tone plan of an 802.11ax WLAN system.Accordingly, when using a tone plan of a 4×996-tone RU in the 320 MHzband, D_(TM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM)=20 in a 996-tone RU).

When the wideband is a 240 MHz band, the 3×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, and a third 996-tone RUby the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, and a third bit streamfor the third 996-tone RU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. That is, the constellation mapping is firstperformed per frequency segment, and, then, the LDPC tone mapping may beperformed afterwards.

The first to third data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to third data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to third data tones may be determined as follows.

t(k)=Di(k mod(N _(SD)/3)/D _(TM))+floor(k*D _(TM)/(N _(SD)/3))

Herein, t(k) is an index of the first to third data tones, D_(TM) is thefirst parameter, k is an index of a tone having the first to third bitstreams mapped thereto, N_(SD) is a number of the data tones, and flooris a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto third bit streams, the first bit stream may be mapped to a fourthdata tone based on a first constellation mapping and mapped to a fifthdata tone based on a second constellation mapping. The second bit streammay be mapped to a sixth data tone based on a third constellationmapping and mapped to a seventh data tone based on a fourthconstellation mapping. The third bit stream may be mapped to an eighthdata tone based on a fifth constellation mapping and mapped to a ninthdata tone based on a sixth constellation mapping.

The first to sixth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fourth to ninth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fourth to ninth data tones may be included in the data tones. Atthis point, the second parameter may be equal to 14.

The second parameter may correspond to an LDPC tone mapping distanceparameter D_(TM_DCM) in a case where the DCM scheme is applied. TheD_(TM_DCM) may be a tone spacing that is used in the LDPC tone mappingin the case where the DCM scheme is applied. Similarly, in the3×996-tone RU, D_(TM_DCM) that is used in the 996-tone RU may be used asit is (D_(TM_DCM)=14 in a 996-tone RU). And, in the 4×996-tone RU,D_(TM_DCM) that is used in the 996-tone RU may be used as it is in the4×996-tone RU (D_(TM_DCM)=14 in a 996-tone RU).

When the DCM is being applied, the fourth, sixth and eighth data tonesmay be lower half tones (or subcarrier k) within a frequency, and thefifth, seven and ninth data tones may be upper half tones (or subcarrierk+N/2) within the frequency. Herein, a tone and a subcarrier may beinterchangeably used.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fourth toninth data tones being spread as much as the second parameter may be asdescribed below.

Indexes of the fourth, sixth, and eighth data tones may be determined asfollows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/3))

Herein, t(k) is an index of the fourth, sixth, and eighth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

Indexes of the fifth, seventh, and ninth data tones may be determined asfollows.

t(k)=D _(TM_DCM)(k−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))+floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3

Herein, t(k) is an index of the fifth, seventh, and ninth data tones,D_(TM_DCM) is the second parameter, k is an index of a tone having thefirst to third bit streams mapped thereto, N_(SD) is a number of thedata tones, and floor is a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). Thefirst modulation symbol may be mapped to the fourth data tone, and thesecond modulation symbol may be mapped to the fifth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). And, the fourth modulationsymbol may be mapped to the sixth data tone, and the fifth modulationsymbol may be mapped to the seventh data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth mapping constellation andmodulated to a sixth modulation symbol based on the sixth constellationmapping. A bit order of a first bit group for the sixth modulationsymbol may be different from a bit order of a second bit group for thefifth modulation symbol ((B_(4k), B_(4k+1), B_(4k+2),B_(4k+3))−>(B_(4k+1), B_(4k), B_(4k+3), B_(4k+2))) The first and secondbit groups may be included in the third bit stream. And, the fifthmodulation symbol may be mapped to the eighth data tone, and the sixthmodulation symbol may be mapped to the ninth data tone.

When the wideband is a 320 MHz band, the 4×996-tone RU may be dividedinto a first 996-tone RU, a second 996-tone RU, a third 996-tone RU, anda fourth 996-tone RU by the segment parser.

The bit stream may include a first bit stream for the first 996-tone RU,a second bit stream for the second 996-tone RU, a third bit stream forthe third 996-tone RU, and a fourth bit stream for the fourth 996-toneRU.

The first bit stream may be mapped to a first data tone based on theconstellation mapping, and the first data tone may be set to have tonespacing that is equivalent to the first parameter based on the LDPC tonemapping. The second bit stream may be mapped to a second data tone basedon the constellation mapping, and the second data tone may be set tohave tone spacing that is equivalent to the first parameter based on theLDPC tone mapping. The third bit stream may be mapped to a third datatone based on the constellation mapping, and the third data tone may beset to have tone spacing that is equivalent to the first parameter basedon the LDPC tone mapping. The fourth bit stream may be mapped to afourth data tone based on the constellation mapping, and the fourth datatone may be set to have tone spacing that is equivalent to the firstparameter based on the LDPC tone mapping. That is, the constellationmapping is first performed per frequency segment, and, then, the LDPCtone mapping may be performed afterwards.

The first to fourth data tones may be included in the data tones.

That is, the above-described embodiment describes that the LDPC tonemapping may be performed per frequency segment (996-tone RU). Dependingupon the LDPC tone mapping, an operation of first to fourth data tonesbeing spread as much as the first parameter may be as described below.

Indexes of the first to fourth data tones are determined as follows.

t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4))

Herein, t(k) may be an index of the first to fourth data tones, D_(TM)may be the first parameter, k may be an index of a tone having the firstto fourth bit streams mapped thereto, N_(SD) may be a number of the datatones, and floor may be a decreasing function.

A case where DCM is applied in the constellation mapping may also beconsidered. When Dual Carrier Modulation (DCM) is performed on the firstto fourth bit streams, the first bit stream may be mapped to a fifthdata tone based on a first constellation mapping and mapped to a sixthdata tone based on the second constellation mapping. The second bitstream may be mapped to a seventh data tone based on a thirdconstellation mapping and mapped to an eighth data tone based on thefourth constellation mapping. The third bit stream may be mapped to aninth data tone based on a fifth constellation mapping and mapped to atenth data tone based on the sixth constellation mapping. The fourth bitstream may be mapped to an eleventh data tone based on a seventhconstellation mapping and mapped to a twelfth data tone based on theeighth constellation mapping.

The first to eighth constellation mappings may be one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme. However, when the DCM is not applied, the constellation mappingmay be one modulation scheme among a BPSK scheme, a QPSK scheme, a16-QAM scheme, a 64-QAM scheme, a 256-QAM scheme or a 1024-QAM scheme.

Each of the fifth to twelfth data tones may be set to have tone spacingthat is equivalent to a second parameter based on the LDPC tone mapping.The fifth to twelfth data tones may be included in the data tones. Thesecond parameter may be equal to 14. Details on the second parameter aredescribed above.

When the DCM is being applied, the fifth, seventh, ninth and eleventhdata tones may be lower half tones within a frequency. And, the sixth,eighth, tenth and twelfth data tones may be upper half tones within thefrequency.

Similarly, even in a case where the DCM is applied, it is described thatthe LDPC tone mapping may be performed per frequency segment (996-toneRU). Depending upon the LDPC tone mapping, an operation of fifth totwelfth data tones being spread as much as the second parameter may beas described below.

Indexes of the fifth, seventh, ninth and eleventh data tones may bedetermined as follows.

t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4))

Herein, t(k) may be an index of the fifth, seventh, ninth and eleventhdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

Indexes of the sixth, eighth, tenth and twelfth data tones aredetermined as follows.

t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))+floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4

Herein, t(k) may be an index of the sixth, eighth, tenth and twelfthdata tones, D_(TM_DCM) may be the second parameter, k may be an index ofa tone having the first to fourth bit streams mapped thereto, N_(SD) maybe a number of the data tones, and floor may be a decreasing function.

For example, if the first and second constellation mappings are the BPSKmodulation scheme, the first bit stream may be modulated to a firstmodulation symbol based on the first constellation mapping and modulatedto a second modulation symbol based on the second constellation mapping.The second modulation symbol may be generated by applying phase rotationto the first modulation symbol (d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). And,the first modulation symbol may be mapped to the fifth data tone, andthe second modulation symbol may be mapped to the sixth data tone.

For example, if the third and fourth constellation mappings are the QPSKmodulation scheme, the second bit stream may be modulated to a thirdmodulation symbol based on the third constellation mapping and modulatedto a fourth modulation symbol based on the fourth constellation mapping.The fourth modulation symbol may be a complex conjugate of the thirdmodulation symbol (d_(k+NSD)=conj(d_(k))). The fourth modulation symbolmay be mapped to the seventh data tone, and the fifth modulation symbolmay be mapped to the eighth data tone.

For example, if the fifth and sixth constellation mappings are the16-QAM modulation scheme, the third bit stream may be modulated to afifth modulation symbol based on the fifth constellation mapping and asixth modulation symbol based on the sixth constellation mapping. A bitorder of a first bit group for the sixth modulation symbol may bedifferent from a bit order of a second bit group for the fifthmodulation symbol ((B_(4k), B_(4k+1), B_(4k+2), B_(4k+3))−>(B_(4k+1),B_(4k), B_(4k+3), B_(4k+2))). The first and second bit groups may beincluded in the third bit stream. The fifth modulation symbol may bemapped to the ninth data tone, and the sixth modulation symbol may bemapped to the tenth data tone.

For example, if the seventh and eighth constellation mappings are theBPSK modulation scheme, the fourth bit stream may be modulated to aseventh modulation symbol based on the seventh constellation mapping andmodulated to an eighth modulation symbol based on the eighthconstellation mapping. The eighth modulation symbol may be generated byapplying phase rotation to the seventh modulation symbol(d_(k+NSD)=d_(k)×e^(j(k+NSD)*pi)). The seventh modulation symbol may bemapped to the eleventh data tone, and the eighth modulation symbol maybe mapped to the twelfth data tone.

The 3×996-tone RU may include 48 pilot tones and 2940 data tones. And,the 4×996-tone RU may include 64 pilot tones and 3920 data tones.

Furthermore, the PPDU may further include a Legacy-Signal (L-SIG) field,a Repeated Legacy-Signal (RL-SIG) field, an EHT-Short Training Field(STF), an EHT-Long Training Field (LTF). The EHT-SIG field may includean EHT-SIG-A field and an EHT-SIG-B field. The EHT-SIG field may furtherinclude an EHT-SIG-C field.

The foregoing technical features of the present specification areapplicable to various applications or business models. For example, theforegoing technical features may be applied for wireless communicationof a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field of study on artificialintelligence or methodologies for creating artificial intelligence, andmachine learning refers to a field of study on methodologies fordefining and solving various issues in the area of artificialintelligence. Machine learning is also defined as an algorithm forimproving the performance of an operation through steady experiences ofthe operation.

An artificial neural network (ANN) is a model used in machine learningand may refer to an overall problem-solving model that includesartificial neurons (nodes) forming a network by combining synapses. Theartificial neural network may be defined by a pattern of connectionbetween neurons of different layers, a learning process of updating amodel parameter, and an activation function generating an output value.

The artificial neural network may include an input layer, an outputlayer, and optionally one or more hidden layers. Each layer includes oneor more neurons, and the artificial neural network may include synapsesthat connect neurons. In the artificial neural network, each neuron mayoutput a function value of an activation function of input signals inputthrough a synapse, weights, and deviations.

A model parameter refers to a parameter determined through learning andincludes a weight of synapse connection and a deviation of a neuron. Ahyper-parameter refers to a parameter to be set before learning in amachine learning algorithm and includes a learning rate, the number ofiterations, a mini-batch size, and an initialization function.

Learning an artificial neural network may be intended to determine amodel parameter for minimizing a loss function. The loss function may beused as an index for determining an optimal model parameter in a processof learning the artificial neural network.

Machine learning may be classified into supervised learning,unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neuralnetwork with a label given for training data, wherein the label mayindicate a correct answer (or result value) that the artificial neuralnetwork needs to infer when the training data is input to the artificialneural network. Unsupervised learning may refer to a method of trainingan artificial neural network without a label given for training data.Reinforcement learning may refer to a training method for training anagent defined in an environment to choose an action or a sequence ofactions to maximize a cumulative reward in each state.

Machine learning implemented with a deep neural network (DNN) includinga plurality of hidden layers among artificial neural networks isreferred to as deep learning, and deep learning is part of machinelearning. Hereinafter, machine learning is construed as including deeplearning.

The foregoing technical features may be applied to wirelesscommunication of a robot.

Robots may refer to machinery that automatically process or operate agiven task with own ability thereof. In particular, a robot having afunction of recognizing an environment and autonomously making ajudgment to perform an operation may be referred to as an intelligentrobot.

Robots may be classified into industrial, medical, household, militaryrobots and the like according uses or fields. A robot may include anactuator or a driver including a motor to perform various physicaloperations, such as moving a robot joint. In addition, a movable robotmay include a wheel, a brake, a propeller, and the like in a driver torun on the ground or fly in the air through the driver.

The foregoing technical features may be applied to a device supportingextended reality.

Extended reality collectively refers to virtual reality (VR), augmentedreality (AR), and mixed reality (MR). VR technology is a computergraphic technology of providing a real-world object and background onlyin a CG image, AR technology is a computer graphic technology ofproviding a virtual CG image on a real object image, and MR technologyis a computer graphic technology of providing virtual objects mixed andcombined with the real world.

MR technology is similar to AR technology in that a real object and avirtual object are displayed together. However, a virtual object is usedas a supplement to a real object in AR technology, whereas a virtualobject and a real object are used as equal statuses in MR technology.

XR technology may be applied to a head-mount display (HMD), a head-updisplay (HUD), a mobile phone, a tablet PC, a laptop computer, a desktopcomputer, a TV, digital signage, and the like. A device to which XRtechnology is applied may be referred to as an XR device.

The claims recited in the present specification may be combined in avariety of ways. For example, the technical features of the methodclaims of the present specification may be combined to be implemented asa device, and the technical features of the device claims of the presentspecification may be combined to be implemented by a method. Inaddition, the technical characteristics of the method claim of thepresent specification and the technical characteristics of the deviceclaim may be combined to be implemented as a device, and the technicalcharacteristics of the method claim of the present specification and thetechnical characteristics of the device claim may be combined to beimplemented by a method.

What is claimed is:
 1. A method in a wireless local area network (WLAN)system, the method comprising: receiving, by a receiving station (STA),a Physical Protocol Data Unit (PPDU) from a transmitting STA; anddecoding, by the receiving STA, the PPDU, wherein the PPDU includes adata field, wherein the data field is received through a 3×996-toneMulti resource unit (MRU) or a 4×996-tone MRU, wherein Low DensityParity Check (LDPC) tone demapping is performed in each 80 MHz frequencysubblock of the 3×996-tone MRU or the 4×996-tone MRU based on a D_(TM),and wherein the D_(TM) is equal to
 20. 2. The method of claim 1, whereinthe data field is generated based on a bit stream, wherein the bitstream is mapped to the data tones based on a constellation mapping,wherein the data tones are configured to have a tone spacing that isequivalent to the D_(TM) based on a LDPC tone mapping, wherein the bitstream is divided per frequency segment by a segment parser before theconstellation mapping is performed, wherein the constellation mappingand the LDPC tone mapping are performed per frequency segment, andwherein a size of one frequency segment is equal to a 996-tone RU. 3.The method of claim 2, wherein the 3×996-tone MRU is divided into afirst 996-tone RU, a second 996-tone RU, and a third 996-tone RU by thesegment parser, wherein the bit stream includes a first bit stream forthe first 996-tone RU, a second bit stream for the second 996-tone RU,and a third bit stream for the third 996-tone RU, wherein the first bitstream is mapped to a first data tone based on the constellationmapping, wherein the first data tone is set to have tone spacing that isequivalent to the D_(TM) based on the LDPC tone mapping, wherein thesecond bit stream is mapped to a second data tone based on theconstellation mapping, wherein the second data tone is set to have tonespacing that is equivalent to the D_(TM) based on the LDPC tone mapping,wherein the third bit stream is mapped to a third data tone based on theconstellation mapping, wherein the third data tone is set to have tonespacing that is equivalent to the DIM based on the LDPC tone mapping,and wherein the first to third data tones are included in the datatones.
 4. The method of claim 3, wherein indexes of the first to thirddata tones are determined as follows:t(k)=D _(TM)(k mod(N _(SD)/3)/D _(TM))+floor(k*D _(TM)/(N _(SD)/3)),wherein t(k) is an index of the first to third data tones, wherein k isan index of a tone having the first to third bit streams mapped thereto,wherein N_(SD) is a number of the data tones, and wherein floor is adecreasing function.
 5. The method of claim 4, wherein, when DualCarrier Modulation (DCM) is performed on the first to third bit streams,the first bit stream is mapped to a fourth data tone based on a firstconstellation mapping and mapped to a fifth data tone based on a secondconstellation mapping, wherein the second bit stream is mapped to asixth data tone based on a third constellation mapping and mapped to aseventh data tone based on a fourth constellation mapping, wherein thethird bit stream is mapped to an eighth data tone based on a fifthconstellation mapping and mapped to a ninth data tone based on a sixthconstellation mapping, wherein the first to sixth constellation mappingsare one modulation scheme among a Binary Phase Shift Keying (BPSK)scheme, a Quadrature Phase Shift Keying (QPSK) scheme or a 16-QuadratureAmplitude Modulation (QAM) scheme, wherein each of the fourth to ninthdata tones is set to have tone spacing that is equivalent to aD_(TM_DCM) based on the LDPC tone mapping, wherein the fourth to ninthdata tones are included in the data tones, and wherein the D_(TM_DCM) isequal to
 14. 6. The method of claim 5, wherein the fourth, sixth andeighth data tones are lower half tones within a frequency, and whereinthe fifth, seven and ninth data tones are upper half tones within thefrequency.
 7. The method of claim 6, wherein indexes of the fourth,sixth, and eighth data tones are determined as follows:t(k)=D _(TM_DCM)(k mod(N _(SD)/3)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/3)), wherein t(k) is an index of the fourth, sixth, and eighthdata tones, wherein k is an index of a tone having the first to thirdbit streams mapped thereto, wherein N_(SD) is a number of the datatones, and wherein floor is a decreasing function.
 8. The method ofclaim 6, wherein indexes of the fifth, seventh, and ninth data tones aredetermined as follows:t(k)=D _(TM_DCM)((k−N _(SD)/3)mod(N _(SD)/3)/D _(TM_DCM))floor((k−N_(SD)/3)*D _(TM_DCM)/(N _(SD)/3))+N _(SD)/3, wherein t(k) is an index ofthe fifth, seventh, and ninth data tones, wherein k is an index of atone having the first to third bit streams mapped thereto, whereinN_(SD) is a number of the data tones, and wherein floor is a decreasingfunction.
 9. The method of claim 6, wherein, if the first and secondconstellation mappings are the BPSK modulation scheme, the first bitstream is modulated to a first modulation symbol based on the firstconstellation mapping and modulated to a second modulation symbol basedon the second constellation mapping, wherein the second modulationsymbol is generated by applying phase rotation to the first modulationsymbol, and wherein the first modulation symbol is mapped to the fourthdata tone and the second modulation symbol is mapped to the fifth datatone.
 10. The method of claim 6, wherein, if the third and fourthconstellation mappings are the QPSK modulation scheme, the second bitstream is modulated to a third modulation symbol based on the thirdconstellation mapping and modulated to a fourth modulation symbol basedon the fourth constellation mapping, wherein the fourth modulationsymbol is a complex conjugate of the third modulation symbol, andwherein the fourth modulation symbol is mapped to the sixth data toneand the fifth modulation symbol is mapped to the seventh data tone. 11.The method of claim 6, wherein, if the fifth and sixth constellationmappings are the 16-QAM modulation scheme, the third bit stream ismodulated to a fifth modulation symbol based on the fifth mappingconstellation and modulated to a sixth modulation symbol based on thesixth constellation mapping, wherein a bit order of a first bit groupfor the sixth modulation symbol is different from a bit order of asecond bit group for the fifth modulation symbol, wherein the first andsecond bit groups are included in the third bit stream, and wherein thefifth modulation symbol is mapped to the eighth data tone and the sixthmodulation symbol is mapped to the ninth data tone.
 12. The method ofclaim 2, wherein the 4×996-tone MRU is divided into a first 996-tone RU,a second 996-tone RU, a third 996-tone RU, and a fourth 996-tone RU bythe segment parser, wherein the bit stream includes a first bit streamfor the first 996-tone RU, a second bit stream for the second 996-toneRU, a third bit stream for the third 996-tone RU, and a fourth bitstream for the fourth 996-tone RU, wherein the first bit stream ismapped to a first data tone based on the constellation mapping, whereinthe first data tone is set to have tone spacing that is equivalent tothe D_(TM) based on the LDPC tone mapping, wherein the second bit streamis mapped to a second data tone based on the constellation mapping,wherein the second data tone is set to have tone spacing that isequivalent to the D_(TM) based on the LDPC tone mapping, wherein thethird bit stream is mapped to a third data tone based on theconstellation mapping, wherein the third data tone is set to have tonespacing that is equivalent to the D_(TM) based on the LDPC tone mapping,wherein the fourth bit stream is mapped to a fourth data tone based onthe constellation mapping, wherein the fourth data tone is set to havetone spacing that is equivalent to the D_(TM) based on the LDPC tonemapping, and wherein the first to fourth data tones are included in thedata tones.
 13. The method of claim 12, wherein indexes of the first tofourth data tones are determined as follows:t(k)=D _(TM)(k mod(N _(SD)/4)/D _(TM))+floor(k*D _(TM)/(N _(SD)/4)),wherein t(k) is an index of the first to fourth data tones, wherein k isan index of a tone having the first to fourth bit streams mappedthereto, wherein N_(SD) is a number of the data tones, and wherein flooris a decreasing function.
 14. The method of claim 13, wherein, when DualCarrier Modulation (DCM) is performed on the first to fourth bitstreams, the first bit stream is mapped to a fifth data tone based on afirst constellation mapping and mapped to a sixth data tone based on asecond constellation mapping, wherein the second bit stream is mapped toa seventh data tone based on a third constellation mapping and mapped toan eighth data tone based on a fourth constellation mapping, wherein thethird bit stream is mapped to a ninth data tone based on a fifthconstellation mapping and mapped to a tenth data tone based on a sixthconstellation mapping, wherein the fourth bit stream is mapped to aneleventh data tone based on a seventh constellation mapping and mappedto a twelfth data tone based on a eighth constellation mapping, whereinthe first to eighth constellation mappings are one modulation schemeamong a Binary Phase Shift Keying (BPSK) scheme, a Quadrature PhaseShift Keying (QPSK) scheme or a 16-Quadrature Amplitude Modulation (QAM)scheme, wherein each of the fifth to twelfth data tones is set to havetone spacing that is equivalent to a D_(TM_DCM) based on the LDPC tonemapping, wherein the fifth to twelfth data tones are included in thedata tones, and wherein the D_(TM_DCM) is equal to
 14. 15. The method ofclaim 14, wherein the fifth, seventh, ninth and eleventh data tones arelower half tones within the frequency, and wherein the sixth, eighth,tenth and twelfth data tones are upper half tones within the frequency.16. The method of claim 15, wherein indexes of the fifth, seventh, ninthand eleventh data tones are determined as follows:t(k)=D _(TM_DCM)(k mod(N _(SD)/4)/D _(TM_DCM))+floor(k*D _(TM_DCM)/(N_(SD)/4)), wherein t(k) is an index of the fifth, seventh, ninth andeleventh data tones, wherein k is an index of a tone having the first tofourth bit streams mapped thereto, wherein N_(SD) is a number of thedata tones, and wherein floor is a decreasing function.
 17. The methodof claim 15, wherein indexes of the sixth, eighth, tenth and twelfthdata tones are determined as follows:t(k)=D _(TM_DCM)((k−N _(SD)/4)mod(N _(SD)/4)/D _(TM_DCM))floor((k−N_(SD)/4)*D _(TM_DCM)/(N _(SD)/4))+N _(SD)/4, wherein t(k) is an index ofthe sixth, eighth, tenth and twelfth data tones, wherein k is an indexof a tone having the first to fourth bit streams mapped thereto, whereinN_(SD) is a number of the data tones, and wherein floor is a decreasingfunction.
 18. A method in a wireless local area network (WLAN) system,the method comprising: generating, by a transmitting station (STA), aPhysical Protocol Data Unit (PPDU); and transmitting, by thetransmitting STA, the PPDU to a receiving STA, wherein the PPDU includesa data field, wherein the data field is transmitted through a 3×996-toneMulti resource unit (MRU) or a 4×996-tone MRU, wherein Low DensityParity Check (LDPC) tone mapping is performed in each 80 MHz frequencysubblock of the 3×996-tone MRU or the 4×996-tone MRU based on a arm, andwherein the D_(TM) is equal to
 20. 19. A receiving station (STA) in awireless Local Area Network (LAN), the receiving STA comprising: amemory; a transceiver; and a processor operatively coupled to the memoryand the transceiver, wherein the processor is configured to: receive aPhysical Protocol Data Unit (PPDU) from a transmitting STA; and decodethe PPDU, wherein the PPDU includes a data field, wherein the data fieldis received through a 3×996-tone Multi resource unit (MRU) or a4×996-tone MRU, wherein Low Density Parity Check (LDPC) tone demappingis performed in each 80 MHz frequency subblock of the 3×996-tone MRU orthe 4×996-tone MRU based on a D_(TM), and wherein the D_(TM) is equal to20.
 20. A transmitting station (STA) in a wireless Local Area Network(LAN), the transmitting STA comprising: a memory; a transceiver; and aprocessor operatively coupled to the memory and the transceiver, whereinthe processor is configured to: generate a Physical Protocol Data Unit(PPDU); and transmit the PPDU to a receiving STA, wherein the PPDUincludes a data field, wherein the data field is transmitted through a3×996-tone Multi resource unit (MRU) or a 4×996-tone MRU, wherein LowDensity Parity Check (LDPC) tone mapping is performed in each 80 MHzfrequency subblock of the 3×996-tone MRU or the 4×996-tone MRU based ona arm, and wherein the D_(TM) is equal to 20.